B 110 
C4 

opy 1 



10 




January 21, 1915. 

TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, 

By p. t?ARDON, 

Scientific Assistant, Office of Cereal Investigations. 
(In cooperation with the Utah Agricultural Experiment Station.) 

INTRODUCTION. 

The experimental work at the Nephi (Utah) substation has been 
conducted cooperatively since 1907 by the Office of Cereal Investiga- 
tions of the Bureau of Plant Industry and the Utah Agricultural 
Experiment Station. The memorandum of understanding between 
these two parties specifies that "the objects of these cooperative 
investigations shall be (1) to improve the cereals of the intermountain 
region by introducing or producing better varieties than those now 
grown, especially with regard to drought resistance, yield, quality, 
earhness, etc.; (2) to conduct such other experiments as might seem 
advisable for the accomplishment of the greatest possible good to 
the dry-land interests of the State." Most of the experiments 
which have been conducted have dealt directly with cereal investi- 
gations as specified in the first clause of the memorandum of under- 
standing; but, as provided in clause 2 of this memorandum, a num- 
ber of experiments have been carried on with methods of tillage 
and with minor dry-land crops. 

A preliminary report of all the work at Nephi was published in 
1910.^ This report was rather general in its nature, owing to the 

1 The Nephi substation was established in 1903 by the Utah Agricultural Experiment Station. From 
that time until July 1, 1907, it was operated as one of several "county farms" located at various points 
in the State. Prof. L. A. Merrill, agronomist of the Utah station, directed the work from 1903 to 1905. 
Thereafter until 1907 it was under the direction of Prof. W. M. Jardine, agronomist of the Utah station. 
On July 1, 1907, cooperation between the Utah experiment station and the Bureau of Plant Industry 
was effected, and Mr. F. D. Farrell, of the U. S. Department of Agriculture, was placed in charge of the 
substation. He was succeeded on March 15, 1910, by Mr. P. V. Cardon. From the time of the establish- 
ment of the station until July 1, 1912, at which time he was succeeded by Mr, A. D. Ellison, Mr. Stephen 
B oswell was foreman. From 1907 to 1912 the State of Utah has been represented through Prof. L. A. Merrill, 
agronomist in charge of arid farms. On July 1, 1913, Mr. Ellison succeeded Mr. Cardon as superintendent, 
and Dr. F. S. Harris, agronomist of the Utah station, succeeded Prof. Merrill. 

^ Farrell, F. D. Dry-land grains in the Great Basin. U. S. Dept. Agr., Bur. Plant Indus. Cir. 61, 39 p., 
2 pi., 1910. 

Note. — This bulletin should be of interest to agronomists and to dry-land farmers, particularly in the 
Great Basin area. 

63648°— Bull. 157—15 1 



2 BULLETIN 157, U. S. DEPARTMENT OF AGEICULTURE. ' 

fact that the experiments had been conducted during only a brief 
period and no conclusive results were available. In 1913 a detailed 
report of varietal and improvement work with cereals was issued.^ 
The present bulletin presents the results of the cultivation experi- 
ments with dry-land cereals. 

DESCRIPTION OF THE SUBSTATION. 

A detailed description of the Nephi substation and a full discussion 
of the climatological data collected there were given in a previous 
publication;^ hence, only a brief description of the substation will 
be given here, and, except in special cases, the chmatological factors 
will not be considered further than to give general averages. 

LOCATION. 

The Nephi substation is located 6 miles south of Nephi, in the 
eastern part of Juab County, Utah, near the center of the State. 
It comprises 100 acres of land lying near the top of the north slope 
of the Levan Kidge, which transversely crosses the Juab Valley. 
The top of this ridge is approximately 6,000 feet above sea level 
and about 500 feet higher than the bottom of the valley. When the 
substation was located in 1903, the Levan Ridge was covered with 
a dense growth of sagebrush, from 2 to 5 feet in height. Now, 
dry farming is practiced generally on the ridge and from 150,000 
to 175,000 bushels of winter wheat are produced annually in the 
vicinity of the substation. 

^OIL. 

The soil of the substation, like most soils of the Great Basin, is 
alluvial and very deep. It is reddish brown in color and varies in 
texture from clay loam to sandy loam, the latter appearing most 
generally beneath the 4-foot level. Above this level the soil con- 
tains about 15 per cent of clay. This comparatively high per- 
centage of clay makes the soil ''heavy" and rather difficult to work 
under certain conditions. In wet weather it becomes very sticky, 
while in extremely dry weather that on which a crop has been grown 
becomes very hard. The preparation of a good seed bed, however, 
usually is not difficult. 

RAINFALL. 

The average annual precipitation at the Nephi substation for 1898 
to 1913, inclusive, was 13.4 inches. During this period the annual 
precipitation was above normal 6 years and below normal 10 years. 
The wettest year was 1906, with 18.48 inches precipitation; the 
driest year was 1910, with 9.08 inches. During the progress of the 
experiments reported herein, the annual precipitation was above 

1 Cardon, P. V. Cereal investigations at the Nephi substation. U. S. Dept. Agr. Bul.~30, 50 p., 9 figs., 
1913. 



a' OF G 

m:io 1915 



I- 

TILLAGE AND EOTATION EXPERIMENTS AT NEPHI, UTAH. 3 

normal in 1908 and 1909, with 16.66 and 16.19 inches, respectively; 
^ while in 1910, 1911, 1912, and 1913 it was below normal, with 9.08, 
^ 10.11, 12.61, and 12.34 inches, respectively. The average annual 

-V precipitation for these last four years was only 11.03 inches. 

Most of the annual precipitation of the past 16 years has fallen 
^^y^ during the months of March, April, and May, the latter month having 
the highest average. The months of June and July have been by 
far the driest months. A large part of the precipitation from Novem- 
ber to March, inclusive, has fallen in the form of snow. 

Most of the rainstorms at Nephi have been small and generally 
almost neghgible. This is especially true of the storms which have 
occurred from March to August, inclusive. Such showers are of 
little value to the crops, because they faU upon a hot, dry surface 
and the moisture is soon lost by evaporation. It has been observed 
that showers of less than 0.5 inch are of little value when considered 
singly. When wet days follow each other consecutively, however, 
thus reducing the evaporation and leaving the surface soil wet, a fall 
of even 0.5 inch of rain is of value. 

EVAPORATION, i 

The average evaporation at Nephi during the six months from 
April to September, inclusive, has been about 45 inches. The lowest 
total evaporation, 40.53 inches, was recorded in 1909; the highest, 
50.26 inches, was recorded in 1910. The lowest average daily evapo- 
ration has been recorded in April and the highest in July; however, 
there was little difference in the evaporation of June, July, and 
August. 

WIND. 

Strong winds or protracted hot winds are practically unknown in 
the vicinity of the Nephi substation, while many summer days pass 
without any appreciable movement in the atmosphere. When wind 
does blow, it is usually from the south or southwest in the morning, 
changing gradually during the day until by evening it is blowing from 
the north or northwest. The average velocity for ajiy one day sel- 
dom reaches 10 miles an hour. 

TEMPERATURE. 

The highest mean and maximum monthly temperatures during the 
growing season have been recorded in July, while the lowest have 
been recorded in April and October. No records have been kept 
from November to March, inclusive. Comparatively low tempera- 
tures are reached in winter, sometimes as low as —20° F., but serious 
injury to the fall-sown crops does not result if the ground is covered 



1 Instruments for measuring evaporation, wind velocitj', and temperature, and the apparatus used in 
making soil-moisture determinations v/ere furnished by the Biophysical Laboratory of the Bureau of Plant. 
Industry, which is cooperating in the work at Nephi. 



4 BULLETIN 157j U. S. DEPARTMENT OF AGRICULTURE. 

with snow. When there is no snow, however, winterkilUng of fall- 
sown cereals is not uncommon. 

Only two mojiths of the year, July and August, have been free 
from frost. Normally, however, there are from 90 to 100 days in the 
frost-free period, extending from June 15 to September 15. 

EXPERIMENTAL WORK. 

All experiments were conducted under field conditions, the treat- 
ment differing from common farm practice only in the tillage method 
under test. 

DESCRIPTION OF PLATS. 

Rectangular tenth-acre plats were used for all experiments except 
one, in which fifth-acre plats were used. The tenth-acre plats were 
36 by 121 feet, while the fifth-acre plats were 72 by 121 feet. The 
plats lay in series running north and south. The series were in pairs, 
the two in each pair being separated from each other by a 5-foot alley, 
while between the pairs of series there were roads 13 feet wide. The 
plats within each series were separated by 5-foot alleys. Thus, each 
plat was separated from the others by a 5-foot alley on two sides and 
one end and by a 13-foot road on the other end. 

Two sets of plats were used for each experiment, except in the case 
of the continuous-cropping test. These two sets of plats permitted 
the alternate cropping and fallowing of each plat, a practice which was 
followed regularly. 

SOIL-MOISTURE DATA. 

Soil-moisture data were collected on most fallow plats and on 
some cropped plats. The number of samples taken varied with the 
plan of the experiment. Soil tubes were used in samphng, the soil 
being taken out in foot sections to depths of 6 to 10 feet. Each foot 
section was placed in a soil can, which was immediately covered 
with a close-fitting lid and taken soon after to the laborator}^. From 
two to four cores were taken from each plat on each day that it was 
sampled. 

The moist weight of each sample was obtained soon after its 
arrival in the laboratory. In no case was the weighing delayed 
more than half a day, the sampling usually being done in the fore- 
noon and the weighing in the afternoon. After the moist weights 
were obtained, the samples were placed in an asbestos-board oven, 
where they were subjected to an average temperature of 110° C. 
They were left in the oven until constant weight was reached and 
then the dry weight of each sample was determined. The difference 
between the moist and the dry weights of the sample was then 
divided by the dry weight of the sample, to get the percentage of 
moisture. An average of the moisture content of all samples taken 
on a plat was considered the average moisture content of the plat. 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 5 
TREATMENT OF THE CROP. 

Methods employed. — The Turkey winter wheat (C. I. No. 2998), a 
hard, red variety, was used in all the experiments except where 
othermse stated. Except in the tests dealing directly with seeding 
problems, the plats of each test were sown on the same date, at a 
uniform depth, and at a uniform rate (3 pecks per acre). After 
seeding, no cultivation was given until the following spring. Then, 
if deemed advisable, the plats were harrowed with a spike-tooth 
harrow to break the crust, which usually had formed as a result of 
conditions in ^\dnter and early spring. The breaking of the crust was 
intended to check evaporation and to stimulate the plants. One har- 
rowing was usually all the cultivation the crops received. Occasion- 
ally, however, weeding w^as necessary, and when hoes were used such 
weeding might be considered as cultivation. 

The crops were harvested with a binder, each plat being cut sepa- 
rately, usually w^hen the grain was in the hard-dough" stage. The 
bundles were always shocked, and then the plat was raked in order to 
prevent loss from fallen heads. The shocks generally stood in the 
field from three to four weeks before thrashing commenced. 

The grain of each plat was thrashed separately. Before thrashing, 
the entire crop was weighed. The weight of the grain after thrashing 
was subtracted from the total weight of the crop, thus giving the 
weight of straw per plat. The weight of straw or grain, multiphed 
by 5 or 10, according to the size of the plat, gave the yield per acre. 
The acre 3rield of grain in pounds was then divided by the standard 
w^eight per bushel to get the yield per acre in bushels. 

Sequence of operations. — The experiments here reported will be dis- 
cussed in the follomng order, which is based upon their relation to 
the sequence of operations necessary to dry-land crop production: 
Stubble treatment after harvest, plowing, cultivation of fallow, 
seeding the crop, cultivation of the crop, harvesting the crop, fre- 
quency of cropping, and diversity of the crops in the rotation. 

STUBBLE TREATMENT AFTER HARVEST. 

In ordinary practice in this region no cultivation precedes the 
plowing of the plats; however, to determine the value of different 
methods of treating the stubble land previous to the time of plowing, 
two tests were inaugurated in the fall of 1911. These tests have been 
(1) the burning of the stubble, as compared with plowing it under; 
and (2) the disking of the stubble immediately after harvest, as com- 
pared with no treatment of the stubble previous to plowing. Neither 
of these tests has been in progress long enough to give any dependable 
information. 



6 



BULLETIN 157, U. S. DEPAETMEXT OF AGEICULTUEE. 



PLOWING. 

In the plomng experiments at the Xephi substation comparisons 
have been made between spring and fall plowing; subsoihng, deep 
plowing, and shallow plowing; also between deep fall plo^ving followed 
by shallow spring plowing and shallow fall plowing followed by deep 
spring plowing. Most of the experiments have been in progress since 
1908, and enough data are available to warrant a rather full discussion 
at this time. 

Fall and Spring Plowing. 

Since the test of fall and spring plowing was commenced in the 
fall of 1908, four tenth-acre plats have been used, thus permitting 
the practice of alternately cropping and fallowing the plats. The 
use made of each plat in each year since 1908 is shown in Table I. 



Table I. — Use of plats at the Nephi substation for the years 1908 to 1913. inclusive. 



Plat. 


1908 


1909 


1910 


1911 


1912 


1913 


12A... 
33 A 


Winter -wheat. 
do 


Fallow 

do 


Winter wheat. 
do 


Fallow 

do 


Winter wheat. 
do 


Fallow. 
Do. 

Winter wheat. 
Do. 


15P... 
16T) 


Fallow 


Vv' inter wheat. 
do 


Fallow 


Winter wheat. 
do 


Fallow 




do 


do 













From 1904 to 1908 the plats were alternately fallowed and cropped 
to winter wheat in the same manner indicated above. During these 
four years all plats received practically uniform treatment, being 
plowed in the fall and allowed to He until the spring of the following 
year, when they were double disked and harrowed and then fallowed, 
with normal treatment until seeding time in the fall. 

In the fall of 1908 plat 13A was plowed as usual, while plat 12A 
was not plowed until the spring of 1909. During the summer of 
1909 the plats received uniform treatment. In the fall of 1909 plats 
15D and 16D were segregated as alternates to plats 12 A and 13A in 
this experiment. Plat 16D was plowed in the fall and left without 
further cultivation until the follo^^ing spring. Plat 15D was plowed 
in the spring of 1910. Both plats were fallow during 1910 and 
received the same cultivation. 

It will be noticed that during the last four years each of the plats 
in this test has been fallow two summers and has produced two 
crops of winter wheat, a total of four crops; that each year there have 
been two fallow plats and two cropped plats; that one plat of each 
pair has been plowed in the fall and the other in the spring; and that 
subsequent treatment has been as nearly the same in all cases as 
possible. 

In studying the relative value of spring and fall plowing, moisture 
conservation, yield per acre, and cost of production have been used 
as bases of comparison. 



TILLAGE AXD EOTATIOX EXPEKIMEXTS AT XEPHI^ UTAH. 



MOISTURE CONTEXT OF FALLOW. 

Much of the argument m favor of fall plo^ving has been based 
upon the belief that the rough sm^face of fall-plowed land is in 
better condition than unplowed stubble land for absorbing the 
winter precipitation. For the purpose of determining the accuracy 
of this theory, soil-moisture studies were made in connection with 
the experiment discussed here. Soil samples were taken to a depth 
of 6 feet from each fallow plat at the beginnuig, in the middle, and 
at the end of the season, and the moisture content of each foot 
section was determined, as previously described in this bulletin. 
The data thus collected during the four years from 1909 to 1912, 
inclusive, are presented in Table II, which shows the annual and 
average percentages of moistm^e m each foot of soil and the average 
percentages in the first 6 feet of soil on each of the fallow plats in 
April, June, and September. 

Table II. — Annual and average percentages of moisture for each of the first 6 feet of soil 
in fallow plats in a test of spring plowing compared tcith fall plou ing at the Nephi 
substation, samples taken in April. June, and September, for the ijears 1909 to 1912, 
inclusive. 



Season and depth of 
sampling. 



Spring plowing 

1 foot 

2 feet 

3 feet 

4 feet 

5 feet 

6 feet 

Average. 

Fall plowing: 

1 foot 

2 feet 

3 feet 

4 feet 

5 feet 

6 feet 

Averase . 



Date of determination. 



1909 



1910 



^ ! 



20. 60115.90 17.05 
20.37 19.45 19.00 



21.27 
1.25 



12.35,11 
18.9318. 38 



20. 10,18. SO 20. 45|20. 50.18. 70 17. 65 
:20. 10 19. 10 20. 15i21. 07 IS. 4S 15. 7S 
IS. 70 19. 17 19. 10'21. 40 20. 10 16. SS 
19. 30 19. 05 IS. 40 19. 05 18. 80 17. 80 



1911 



1912 



20. 48 15. 86,13. 09 14. 98 14. 18 12. 59 



19.33|14. 5 
20.9619. 38 

21. 02 19. 09116. 93;21. 88 19. 70 19. 55i20. 87|l9. 



19. 57119.56 18. 10 22. 65 19. 80 19. 4/ 



Four-year 
average. 



19.3411 



13.65 
18. 74 
18.64 



,17. 12;22. 55 20. 50 19. 63 20. 76 IS. 96 18. 17 



17. 04 16. 69 15. 34'22. 07 20. 34 17. SO 19. 80 19. OS 17. 28 
17.20 17. 7< 17. 73 IS. 60 IS. 20 15. 05,18. 54,18. 4617.24 



. . 19. 86 18. 5819. 02120. 7617. 8916. 40 19.il 17. 76,16. 3S 20. 46,18. 79 17. 35 20. 04!l8. 25 17. 29 



21. 10 14. 

'20.92 19. 
20. 00 19. 
19. 80 IS. 
17.97 17. 
18.65 20. 



I 

6017.65 
6017.60 
6019.05 
85 18. 95 
90 17. 75 
32 19.30 



20. 93 14. 45 12. S3 21. 29 17. 98ll2. 26121. 55;i5. 82 13. 29 21. 22!l5. 71 14. 01 
20.8819. 4S IS.Uo 21.59 19. 60'17. 76 21. 45il9. 63 IS. 67 21. 2l!l9. 5818. 02 
20. 13|1S. 2u 17. JO. 03 17. 55 17. 43il9. 62llS. 25 IS. 13 19. 94 IS. 40|l8. 11 
19.80 19.25 17.75 15.2414. 76!l5. 7612. S2 15.21 15.45 16.91 17.0216.98 
19. 1018. 55 17. 05 16. 13 14. 7914. 95ill. 39 13. 30 12. 40 16. 1516. 13!l5. 54 
19. 5719. 80 16. 98 18. 78 16. 75 15. 2514. 99 IS. 40 14. 4':i IS. 00 IS. S2'l6. 50 



19. 74jl8. 48|18. 38 20. 07|18. 29jl6. 75 18. 85|1 



). 90 15. 57,16. 97 16. 
I I I 



1.:.41 IS. 90 17.61.16. 53 



Table II shows (1) that in every case except the second and third 
sampling of 1910 the average percentage of moisture in the 6 feet 
of soil was higher in the spring-plowed plat: (2) that the first foot 
of soil in the fall-plowed plat contained, as a rule, a higher percentage 
of moisture than the first foot of the spring-plowed plat; (3) that 
the slight difference in the moisture content of the second foot of 
the plats favored the fall-plowed plat during the spring and summer, 
while it favored the sprmg-plowed plat at seeding time in the fall; 



8 



BULLETIN 157^ U. S. DEPAETMENT OF AGEICULTUEE. 



(4) that the average moisture content of the third, fourth, and fifth 
feet was invariably in favor of the spring-plowed plat; (5) that there 



/309 /S/O /9// /9/2 Ai/E/?AG£ 




Fig. 1. — Graphs showing the average percentage of moisture in the first 6 feet of soil at the beginning, 
in the middle, and at the end of the fallow season, as found in the spring-plowing and fall-plowing 
tests at the Nephi substation, 1909 to 1912, inclusive. 



was little difference in the moistin-e content of the samples of the 
sixth foot; and (6) that the loss of moisture from spring to fall was 



^U/V£ S/^MPL/A/G 



SEPT S/^MPU/VG 


























— 








11 
1 

—th 


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1 
1 




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\ 

\ 




— t- 
1 
1 


1 

U — 






N 

N 


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6 / 2 3 ^ S- 
D£:/=TH /A/ /^E-JET 











































h 
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Fig. 2. — Graphs comparing the average percentage of moisture in each of the upper 6 feet of soil at the 
beginning, in the middle, and at the end of the fallow season, as found in the spring-plowing and fall- 
plowing tests at the Nephi substation, 1909 to 1912, inclusive. 

about the same on both plats. These facts are shown graphically 
in figures 1, 2, and 3. 



TILLAGE AXD EOTATION EXPEEIMEKTS AT KEPHI^ UTAH. 



9 



The facts thus brought out seem to indicate that at Nephi stubble 
land allows the winter precipitation to penetrate to greater depths 
than fall-plowed land and that the loose surface of the fall-plowed 
land retains more of the precipitation of whiter than the compact 
surface of the stubble land. They indicate, further, that when the 
stubble land is plowed in the spring it loses much of the moisture in 
the surface foot, as does also the fall-plowed land when it is replowed 
or double disked, one of these operations always being necessary in 
the spring on fall-plowed land. This is decidedly to the disadvantage 

SPP/A/G PLOlA//A/e F/iLL PLOmA/G 




^ /JPR/L S/1MPL/A/G 

^UA/S I 



I \ -7 ^^^ '^ ^1 \ \ I 

/ 2 3 ^ S- 6 / 2 3 ^ ^ e 
OETPT/V /A/ p^£:r. 

Fig. 3. — Graphs showing the average seasonal decline in percentage of moisture in each of the upper 
6 feet of soil, as found in the spring-plowing and fall-plowing tests at the Nephi substation, 1909 to 
1912, inclusive. 

of the fall-plowed land, which during the winter retains so much 
moisture in the surface foot. Lastly, the facts brought out show 
that the moisture content of the soil below the surface foot was prac- 
tically constant throughout the season. This was favorable to the 
spring-plowed land, which had allowed the moisture to penetrate 
into the third, fourth, and fifth feet. That winter wheat makes use 
of moisture found at these depths is evidenced by the fact that in 
1910 the roots of a winter- wheat plant growing on the station were 
found to extend more than 7 feet below the surface of the ground. As 
the spring-plowed plats had some advantage in soil-moisture content 
below the second foot, the higher yields on these plats were anticipated. 
63648°— Bull. 157—15 2 



10 BULLETIN 157; V. S. DEPARTMENT OF AGRICULTURE. 

YIELD OP GRAIN. 

The annual and average yields of winter wheat in bushels per acre 
from 1910 to 1913, inclusive, are presented in Table III and are com- 
pared graphically in figure 4. 

Table -III.- — Annual and average yields of winter wheat from fall-plowed and spring- 
plowed plats at the Nephi substation, 1910 to 1913, inclusive. 



Yield per acre of grain (bushels). 



Treatment. 














1910 


1911 


1912 


1913 


Average. 


Plowed in spring previous to seeding 


14 


33 


22 


5 


18.5 


Plowed in fall one year before seeding 


12 


29 


22 


4 


16.8 



The yields reported in Table III agree fairly with the moisture data 
reported in Table 11. The average difference in yield of 1.7 bushels 



//V BUSHELS PE/? AC/?£: 
O 2 ^ 6 8 /O /2 /6 /a SO 22 2^ 26 26 30 32 34 




Fig. 4.— Diagram comparing the annual and average j^ields obtained in the spring-plowing and fall- 
plowing tests at the Nephi substation, 1910 to 1913, inclusive. 



per acre favors spring plowing, which has given yields equal to or 
greater than fall plowing each year since the experiment began. 
This small difference in yield, however, is not so important in itseK 
as it is when considered jointly with the cost of production. 

RELATR^E COST OF FALL AND SPRING PLOWING. 

Fall plowing is more difficult than spring plowing, and for this 
reason it generally costs more. The difference in cost at the substa- 
tion has varied between 15 and 25 cents an acre, with an average of 
20 cents. In addition to this, it has been observed that the plats 
wh'icji were spring plowed w^ere more nearly free from weeds and 
volunteer grain during the fallow period than the plats plowed in the 
fall. It was always necessary to replow or double disk the fall- 
plowed plats in the spring, owing to a rather vigorous growth of weeds 
and volunteer grain. Even these operations often failed to destroy 



TILLAGE AXD ROTATION EXPERIMENTS AT NEPHI, UTAH. 11 

all vegetative growth, so that, in order to keep the fallow clean, some 
weeding was necessary two or three times during the summer. It 
seems probable that fall plowing turns under weed seeds and grain 
kernels, some of which lie dormant until they are brought to the 
surface agam the next spring by replowing or disking the land. 
Thus the operation which is intended to destroy all growth induces 
further growth by bringing other seeds into a position favorable to 
germination. Their growth requires frequent weeding of the fallow. 
These extra operations were unnecessary on the spring-plowed plats, 
and consequently the cost of producing crops on these plats was reduced 
to a point substantially below that on the fall-plowed plats. 

The average cost of spring plowing was $1.93 per acre, while fall 
plowing cost $2.13. Replowing the fall-plowed land cost on an 
average $1.85 per acre, while double disking the fall-plow^ed land cost 
about 75 cents per acre, making an average cost of $1.30 and increas- 
ing the cost of fall plowing to $3.43. The subsequent weedmg of the 
fall-plowed land cost about 25 cents per acre. This, added to the 
cost of plowing and replowing or double disking, makes the total cost 
of fall plowing S3. 68, as compared with $1.93 for spring plowing, a 
difference of $1.75 per acre. These figures, of course, do not include 
the cost of cultivating the fallow, seeding and harvesting the crop, 
etc., which was the same on all plats and hence need not be con- 
sidered here. 

It has been shown that spring plowing has given an average yield 
of 1.7 bushels per acre more than fall plowing. The average market 
value of wheat at Nephi during the past four years has been 75 cents 
per bushel. Spring plowing, then, has yielded $1.28 more per acre 
than fall plowing. The extra income added to $1.75, the amount 
saved by spring plowing as compared with fall plowing, makes the 
difference in net return $3.03 per acre in favor of spring plowing. 

The fact that spring plowing at the substation was done as early 
in the year as possible must receive emphasis at this point. The land 
at that time was in good condition for plowing, and it turned over in 
excellent shape. Later plowing was found to be less desirable. For 
this reason it might be advisable for farmers in distributing their 
farm labor to plow enough in the fall to aUow them to plow all the 
rest of their land at the proper time in the spring. This practice is 
followed by many of the more successful farmers in the vicinity of 
Nephi. 

Depth op Fall Plowing. 

Previous to 1908 all of the eight plats used in the faU depth-of- 
plowing test were given treatment as nearly uniform as possible, 
being alternately fallowed and cropped to wdnter wheat. In the fall 
of 1908 four adjacent plats, 16A, 17A, 18A, and 19A, were set aside 
for this test. Alternate plats, 16C, 17Cj 18C, and 19C, were added 



12 BULLETIN 157^ U. S. DEPARTMENT OF AGEICULTURE. 



in the fall of 1909. Since this time the plats have been alternately 
fallowed and cropped to winter wheat, receiving -uniform treatment 
in every case except in the depth of plowing. They were replowed 
or double disked each year in order to destroy weeds and volunteer 
grain. 

The depth of plowing on the diiferent plats in the fall of 1908, 1910, 
and 1912 was as follows: 16A, subsoiled, 18 inches; 17A, subsoded, 
15 inches; 18 A, plowed, 10 inches; 19 A, plowed, 5 inches. The 
depth of plowing on the different plats in the fall of 1909, 1911, and 
1913 was as follows: 16C, subsoiled, 18 inches; 17C, subsoiled, 15 
inches; 18C, plowed, 10 inches; 19C, plowed, 5 inches. 

Table IV. — Annual and average percentages of moisture for each of the first 6 feet of 
soil in plats plowed to different depths at the Nephi substation, samples taken in April, 
June, and September, for the years 1909 to 1912, inclusive. 

SUBSOILED 18 INCHES DEEP. 



Date of determination. 







1909 






1910 






1911 






1912 




Average. 


Depth of sampling. 




































00 




CO 






00 








00 


o 












(N 






o 










(N 


(N 












Apr. 


June 


Sept. 


Apr. 


June 


Sept. 


Apr. 


June 


Sept. 


Apr. 


June 


Sept. 


Apr. 


June, 


Sept. 


1 foot 


22.00 


17.37 


18. 05 


20. 35 


13.13 


13.05 


19.50 


14.83 


15. 95 


20.99 


18.89 


9.68 


20. 71 


16.06 


14. 18 


2 feet 


21.40 


21.35 


20. 40 


20. 70 


19. 48 


19.80 


20. 45 


18. 41 


17. 79 


21.71 


20. 98 


18. 51 


21.07 


20.06 


19. 13 


3 feet 


21.25 


19. 55 


19. 55 


20. 70 


19.33 


16. 53 


15.20 


16. 90 


18.17 


18.61 


19. 60 


17. 33 


18.94 


18. 85 


17.91 


4 feet 


20.00 


19. 45 


19.00 


19. 95 


18.38 


17.65 


13.19 


14. 63 


17.08 


12. 95 


16.65 


14. 98 


16.52 


17. 28 


17.18 


5 feet 


19. 05 


19.50 


18. 65 


19.15 


17. 83 


17. 83 


14.72 


15. 51 


16. 30 


13.35 


14.64 


10. 48 


16.57 


16. 87 


15.82 


6 feet 


19. 50 


20.22 


20. 60 


20.03 


18. 75 


18. 93 


16. 58 


17. 79 


17.46 


12.47 


17.89 


15.91 


17. 15 


18. 66 


18.23 


Average 


20.53 


19.57 


19.38 


20. 15 


17.82 


17.30 


16. 61 


16.35 


17. 12 


16.68 


18. 11 


14.49 


18.49 


17.96 


17.07 



SUBSOILED 15 INCHES DEEP. 



Ifoot... 

2 feet... 

3 feet. .. 

4 feet... 

5 feet . . . 

6 feet... 



Average. 



21.62 
22.40 
20. 65 
20. 20 
18. 50 
19.90 



18.20 
20. 80 
19. 60 
19.15 
18. 30 
21.35 



18.00 20. 27 
19. 70 21. 23 
19. 75'20. 57 
19. 55! 19. 63 
18.90jl7. 75 
20. 25 20. 15 



14.35 14.30 20. 73 
18. 60 20. 25 21.02 

18. 78 18. 4016.70 
17.7017.60 15. 93 
17. 65!l7.28 14. 81 

19. 65 18. 90 18. 20 



20. 54 19. 57 19. 36 19. 93 17. 79 17. 79 17. 90 17. 10 



16. 75 18. 20 
19. 68 19. 66 
13. 47 19. 50 
18.38 17. 98 
15. 20 15. 71 
19.11 19. 22 



I I I I 
26. 9416. 97,13. 82 22. 39 16. 58 16. 08 
21. 50|20. 30 19. 60 21. 54 19. 85 19. 80 
18. 85 16. 57 18. 37 19. 14 17. 11 19. 01 



17. 51 
12. 70 
18. 25 



17. .58 15. 91 18.32 18.20 17. 76 
13.52 13.00 15.94il6.17:i6.22 
19.01:16.11:19. 13 19. 7818.62 



18. 38 19. 29 17. 33 16. 14 19. 41 17. 95:i7. 92 

I I I 



PLOWED 10 INCHES DEEP. 



1 foot 


21.63 16. 40 


17. 70 


20. 95 


14.98 


15.35 


20. 9o!l7. 80 


16.39 


22. 1218.23 


13.9121.4016. 85 


15. 84 


2 feet 


22. 45 21.05 


20.00 


21.97 


18. 70 


20. 45 


18.20|20. 83 


20.03 


21.9019.83 


18. 63 21.13 20.10 


19. 78 


3 feet 


21. 45 19. 80 


19.65 


20.82 


19.25 


18. 68 


17. 84 19. 89 


19. 63 


20. 4018. 64 


18. 09120. 13 19. 40 


19.01 


4 feet 


20.35 18. 85 


18.40 


19.92 


17. 80 


17. 88 


14.46|17. 15 


18. 45 


14. 67 


15. 38 


15. 72 17.35 17. 30 


17. 61 


5 feet 


20. 32 18. 20 


15.95 


20. 90 


18.10 


17. 75 


15. 8016. 14 


17. 08 


11. 35 


13. 22 


13.55 


17. 09 


16.42 


16. 08 


6 feet 


20. 67 20.60 


18.90 


21.52 


18. 88 


18. 88 


17. 99 


18.43 


17. 27 


12.70 


16. 51 


15. 59 


18. 22 


18.61 


17. 66 




21.1419.15 

1 


18. 43 


21.01 


17. 95 


18.17 


17.53 


18.37 


18. 14 


17. 19 


16.97 


15. 92 


19. 22 


18.11 


17. 66 



PLOWED 5 INCHES DEEP. 



1 foot 


21.65 


15. 10 


17.05 


20.90 


15.65 


14. 83 


20. 90 


17. 94 


17.50 


22. 40 


18. 73 


1 

15.20!21.46 


16. 85 


16. 15 


2 feet 


21.85 


20. 40 


18. 70 


21.30 


19.98 


19. 88 


21.38 


20. 54 


19. 55 


24.07 


19.40 


20. 48122.15 


20. 08 


19. 65 


3 feet 


21.20 


19.35 


19.00 


19.08 


17.30 


18. 50 


17. 48 


19.17 


19.44 


19.07 


18.22 


20.1719. 21 


18. 51 


19. 28 


4 feet 


20.30 


18. 50 


18. 60 


18. 23 


16.68 


18. 13 


13.12 


17. 26 


17. 59 


14. 25 


16. 29 


18.1516. 33 


17. 18 


18. 12 


5 feet 


19. 55 


17.92 


18.00 


19.05 


18. 93 


19. 73 


14. 78 


15. 59 


17. 20 


16. 42 


17. 65 


18. 5617. 30 


17. 52 


18.37 


6 feet 


20.00 


18. 95 


19. 70 


16.35 


15.93 


15. 50 


15. 23 


16.59 


17. 19 


16. 20 


15. 65 


14. 75 16. 95 


16. 78 


16. 79 


Average 


20.76 


18.37 


18. 51 


19. 15 


17. 41 


17. 76 


17.15 


17. 85 


18. 08 


18. 74 


17. 66 


17. 8918. 90 

1 


17. 82 


18.06 



V 



TILLAGE AND ROTATION EXPEEIMENTS AT NEPHI, UTAH. 13 

It will be seen from the above that during each year since 1908 
four adjacent plats, each plowed to a different depth, have been 
fallow and that since 1909 these four plats, with four alternates, have 
been cropped or fallowed. This arrangement has afforded an oppor- 
tunity each year to study soil moisture on the fallow plats and yields 
on the cropped plats, as influenced by shallow plowing, deep plowing, 
and subsoihng. 

MOISTURE CONTENT OF FALLOW. 

All of the fallow plats of each year were sampled at the beginning, 
in the middle, and at the end of the season. Samples were taken to 



/303 /3/0 /3// /9/2 AV£y?/^G£ 




I4\ 1 I \ 1 1 \ 1 I 1 1 I 1 1 

Fig. 5.— Graphs showing the average percentage of moistiire in the first 6 feet of soil at the beginning, 
in the middle, and at the end of the fallow season, as found in the spring-plowing and fall-plowing 
tests at the Nephi substation, 1909 to 1912, inclusive. 

a depth of 6 feet, and the moisture content of each foot section was' 
determined separately. Table IV presents the data collected from 
1909 to 1912, inclusive, and shows the annual and average percentage 
of moisture in each foot section of soil and the average of the 6-foot 
section in April, June, and September. 

The data presented in Table IV show (1) that there was very Httle 
difference in the soil-moisture content of these plats in the spring, 
summer, or faU; (2) that aU of the plats uniformly lost much of the 
moisture of the first foot during the spring cultivation necessary to 
rid the plats of weeds and volunteer grain and to prepare them for 
the fallow season; (3) that the moisture below the first foot remained 



14 BULLETIN 157, U. S. DEPAETMENT OF AGEICULTUKE. 



practically the same on all plats during the fallow season; and (4) 
that the average percentage of moisture in the fall was lower for the 
plats subsoiled to a depth of 18 inches than for any of the other plats. 
These facts are shown graphically in figures 5, 6, and 7. 

The points thus brought out show that, so far as soil moisture is 
concerned, there was no advantage in deep plowing or subsoiHng, for 
the moisture content of the plat plowed 5 inches deep (shallow plow- 
ing) was as high as that of any of the others. So far as the prepara- 
tion of a seed bed is concerned, however, it was found that in most 
cases the shallow plowing was less desirable because the stubble was 
not turned under as well as by the deeper plowing. Because of this 
the surface of the shallow-plowed plat usually contained much trash. 



£3 
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SPR/NG SAMPL/A/G 



SUMMEPS/1MPUA/G 



F/^LL S/iMPL/A/G 



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s 












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\ 















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1 

1 / 










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£XPLAA//!T/OA/- 

SOBSO/LED /3" 0££P 

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PLOyi^eO /O" " 

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Fig. 6. — Graphs comparing the average percentage of moisture in each of the upper 6 feet of soil at the 
beginning, in the middle, and at the end of the fallow season, as found in the faU depth-of-plowing 
tests at the Nephi substation, 1909 to 1912, inclusive. 

which interfered somewhat with the operation of the drill when the 
plat was seeded. 

YIELD OF GRAIN. 

The annual and average yields of the plats in these tests are pre- 
sented in Table V and are shown graphically in figure 8. 

Table V. — Annual and average yields of winter wheat on plats used in the dejpth-of- 
plowing tests at the Nephi substation, 1910 to 1913, inclusive. 



Treatment. 



Yield per acre of grain (bushels). 



1910 


1911 


1912 


1913 


Avera^ge. 


14 


28 


18 


4 


16.0 


13 


29 


19 


6 


16.7 


13 


29 


21 


7 


17.5 


12 


27 


20 


10 


17.2 



Subsoiled 18 inches deep 
Subsoiled 15 inches deep, 
Plowed 10 inches deep. . 
Plowed 5 inches deep. . . 



TILLAGE AND ROTATION EXPEEIMENTS AT NEPHI^ UTAH. 



15 



The yields obtained in this test, as shown in Table V, agree with 
the moisture content of the plats, as previously discussed. The 
highest average yield was obtained from the plats plowed 10 inches 
deep, and the lowest average yield was obtained from the plats 
subsoiled 18 inches deep, while the plats plowed 5 inches deep gave 
better yields than those subsoiled 15 inches deep. The widest 
difference in the yields, however, is not significazit. The point most 
strongly emphasized by the results is that there was no material 
difference in the yields obtained from plats plowed at depths varying 
from 5 to 18 inches. 



RELATIVE COST OF PLOWING AND SUBSOELING. 



Since there was no material difPerence in the moisture content or 
in the yields of the plats included in the depth-of-plowing tests, it is 



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'v — 








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— ^ 


V 




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V 




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/J. 


rr 






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i — 





















SUBSO/L£D /S 0££P. 



PLOiV£D /0'0££P 



PLOiVED S DEEP. 



6 I 




Fig. 7. — Graphs showing the average seasonal decline in percentage of moisture in each of the upper 
6 feet of soil, as found in the fall depth-of-plowing tests at the Xephi substation, 1909 to 1913, 
inclusive. 



well to consider the cost of crop production on the plats to determine, 
if possible, the comparative value of each operation. The subsoiled 
plats were first plowed and then subsoiled, the subsoiler following in 
the plow furrow. The draft of the subsoiler was as great as that of 
the plow; hence, the subsoiling entailed twice the expense of plowing 
and did not increase the peld of the plat. For this reason there was 
nothing in favor of and much against subsoihng as tested at Nephi. 

There was so little difference between the yield's of the two plowed 
plats that it is difficult to see any advantage in favor of deep plowing 
over shallow plowing. In fact, when considered from the standpoint 
of net returns, there was no advantage for deep plowing, because of 
the gTeater expense incurred. The most evident point in favor of 
deep plowing seems to be, as previously noted, that it covers the 
stubble better and this obviates some trouble at seeding time. Had 
some plats been plowed at different depths between 5 and 10 
inches and some others plowed at these same depths in the spring 
as well as in the fall, it is possible that some more significant data 



16 



BULLETIN 157^ U. S. DEPARTMENT OF AGRICULTURE. 



would have been obtained. With the data available, however, the 
question seems to be not so much how deep to plow as how well to 
plow. 

Depth of Fall and Spring Plowing. 

As already stated, there is always need in the spring of replowing 
or double disking land that has been plowed the previous fall. Be- 
cause of this condition, an experiment was commenced in 1911 to 
determine whether it is best to plow deep in the fall and then shallow 
in the spring, or vice versa. In this test, plats 24C and 25C have 
been used alternately with plats 25A and 26A. One plat was plowed 



o 
/so 

/3.0 
/2.0 



y/ELD /A/ BL/S/ZELS PER /^ICRE 
8 /O /2 /5» /6 /8 20 22 



26 28 30 



^^^^^^^^^^^^^^^^ 




Fig. 



-Diagram comparing the annual and average yields obtained in the fall depth-of-plowing 
tests at the Nephi substation, 1910 to 1913, inclusive. 



only 3 inches deep in the fall, while the other was plowed 8 inches 
deep at the same time. The following spring the plat which was 
fall plowed 3 inches deep was replowed 8 inches deep, while the other 
plat was replowed only 3 inches deep. These plats were compared 
with an adjacent plat treated according to general practice in the 
region. 

The soil-moisture determinations made in 1912 show no difference 
between the two methods. The yields of 1913, however, shghtly 
favor the plat plowed 8 inches deep in the fall and 3 inches deep in 
the spring, but the difference is not significant. The test must be 
continued for several years before the results will be of value. 



i 

TILLAGE AND ROTATION EXPERIMENTS AT NEPHI^ UTAH. l7 
CULTIVATION OF FALLOW. 

The purpose of the experiments in cultivating fallow land has been 
to determine the value of cultivation as compared with no cultiva- 
tion. Very little has been done to determine the relative value of 
such factors as depth, method, and frequency of cultivation, etc., 
further than to observe and to note differences whenever they were 
apparent. These factors are so variable, however, that the notes 
made do not suggest any established principles. 

Cultivation op Fall-Plowed Fallow. 

Since 1908 two pairs of plats, alternately cropped and fallowed, 
have been used at Nephi in an endeavor to determine the value of 
cultivation as compared with no cultivation of fall-plowed fallow. 
' Two adjacent plats were plowed uniformly in the fall of each year, 
and both were allowed to lie in a rough condition through the follow- 
ing winter. During the next spring and summer one of these plats 
received normal cultivation, while the other was not cultivated. 
Both were seeded uniformly in the fall and the further treatment of 
the plats was identical. These two plats alternated with two other 
plats which received the same treatment. 

The cultivated fallow plat was replowed or double disked in the 
spring after fall plowing, to destroy weeds and volunteer grain. It 
was then harrowed, and during the succeeding summer it was har- 
rowed and weeded as often as necessary. At least three harrowings 
were given the plat — one in the spring, one in the summer, and another 
just prior to the time of seeding; and the plat was weeded once or 
twice. On the other plat, weeds and volunteer grain were allowed 
to grow, but all growth was clipped before it matured, in order to 
minimize subsequent weed trouble. 

moisture content of fallow. 

Soil samples were taken from the fallow plats at the beginning, 
in the middle, and at the end of the season. Six-foot borings were 
made and the moisture content of each foot section was determined 
in the usual manner. The data obtained from these determinations 
are presented in Table VI, which shows the annual and average per- 
centages of moisture in each foot and the average percentages in the 
6 feet in the spring, in the summer, and in the fall for both the culti- 
vated and the uncultivated fallow for the four years 1909 to 1912, 
inclusive. 

63648°— BulL 157—15 3 



18 BULLETIN 157, U. S. DEPARTMENT OF AGEICULTUKE. 



Table VI. — Annual and average percentages of moisture in each of the first 6 feet of soil 
on cultivated and uncultivated fallow at the Nephi substation, samples taken in spring, 
summer, and fall, for the years 1909 to 1912, inclusive. 

FALLOW CULTIVATED NORMALLY. 



Date of determination. 







1909 






1910 






1911 






1912 




Average. 


Depth of sampling. 




































































OC 




(M 


















i 






Apr. 


Junft 


Sept. 


Apr. 


June 


Sept. 


Apr. 


June 


Sept. 


Apr. 


June 


Sept. 


Sprir 


Sum I 


Fall. 


1 foot 


19.22 


16. 35 


17. 15 


14.50 


16.05 


13.53 


18.82 


17.39 


12.52 


21. 67 


14.07 


14. 47 


18.55 


15. 97 


14.42 


2 feet 


19. 60 


19. 65 


16. 55 


18.20 


18. 80 


19.35 


19.69 


19. 53 


17. 74 


22. 06 


19. 87 


18. 88 


19.89 


19. 46 


18.13 


3 feet 


19. 50 


19. 50 


18. 85 


18.95 


17.85 


18.03 


18. 65119. &3 


17. 72 


20. 05 


18.47 


17. 85 


19. 29 


18. 86 


18.11 


4 feet 


19. 40 


18. 90 


18. 70 


19.33 


19.63 


18. 68 


14.95 


18. 80 


16. 56 


13.32 


14.20 


14. 10 


16. 75 


17.88 


17.01 


5 feet 


18.20 


18. 00 


18. 05 


19. 05 


18.33 


19. 15 


13. 41 


20. 80 


15.31 


10. 44 


10. 95 


12. .53 


15.28 


17.02 


16.26 


6 feet 


20.00 


20. 30 


19. 35 


19.30 


18. 80 


18. 45 


17.44 


17.60 


17.89 


15.85 


13.92 


13. 54 


18. 15 


17.66 


17.31 


Average 


19.32 


18. 78 


18.11 


18.22 


18.24 


17. 86 


17. 16 


18. 96 


16.29 


17.23 


15. 25 


15.23 


17.98 


17. 81 


16. 87 



FALLOW NOT CULTIVATED. 



1 foot 


18.60 


12.65 12.30 


12.85 


10. 45 


8. 05 


20.00 


12.83 


9. 61 


20.47 


10.68 


7. 


95 


17. 98 


11. 


65 


9.32 


2 feet 


19. 30 


15. 80 13. 20 


17.37 


14.05 


12.23 


20. 16 


14.99 


12. 98 


20. 75 


12.36 


11. 


46 


19.30 


14. 


30 


12.47 


3 feet 


20. 45 


16. 55 14. 15 


19. 10 


13.28 


11.78 


17. 88 


17. 08 


12.28 


17.21 


12.91 


11. 


18 


18.66 


14. 


96 


12.35 


4 feet 


19.35 


17.55 15.25 


18. 93 


13.80 


10. 38 


12. 03 


14.89 


11.61 


10.83 


11.35 


10. 


74 


15.29 


14. 


40 


12.00 


5 feet 


19. 05 


18. 15 16. 15 


19. 35 


16. IS 


13. 45 


11. 10 


13. 94 


11.20 


11.27 


14.47 


11. 


86 


15. 19 


15. 


69 


13. 17 


6 feet 


20. 57 


20. 42118.95 


19. 10 


16.63 


15.33 


13. 10 


18.11 


12.06 


14.17 


15. 76 


12. 


27 


16. 74 


17. 


73 


14.65 


Average 


19.55 


16.85|l5.00 


17. 79 


14. 06 


11. 87 


15. 71 


15.31 


11.62 


15. 78 


12.92 


To. 


91 


17.20 


14. 


79 


12.34 



Table VI shows that the moisture content of the plats was practi- 
cally uniform in the spring, but that the differences increased 
as the season advanced. The moisture in the cultivated plat re- 
mained practically the same throughout the season, while that of 
the uncultivated plat rapidly decreased until by fall it was reduced 
to a comparatively low point. The first 4 feet seemed to lose more 
moisture than the fifth and sixth. These data are shown graphically 
in figures 9, 10, and 11. The fact that the moisture content of the 
second, third, and fourth feet of the imcultivated plat was reduced 
practically as much as on any of the cropped plats sampled suggests 
that a great deal of the moisture loss from the uncultivated plat was 
due to the growth of weeds and volunteer grain. 

YIELD OF GRAIN. 

The difference in the soil-moisture content of the plats, as shown 
in Table VI and figures 9,10, and 11, is reflected in the yields obtained. 
These are reported in Table VII and are compared graphically in 
figure 12. It wiU be noticed that there is a difference of 4 bushels 
per acre in the average yield for the four years in favor of the culti- 
vated plats. This difference is more than enough to pay for the cul- 
tivation of the faUow. 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 19 



Table VII. — Annual and average yields of winter wheat on cultivated and uncul- 
tivated fallow at the Nephi substation, for the years 1910 to 1913, inclusive. 



Yield per acre of grain (bushels). 



JLICclUliOUl. 


1910 


1911 


1912 


1913 


Average. 


Fallow cultivated 


13 
14 


29 
18 


21 
15 


5 
5 


17 
13 


Fallow not cultivated 





Cultivation of Spring-Plowed Fallow. 

In the spring of 1912 tests similar to the ones last discussed were 
begun on spring-plowed fallow. Both plats produced winter wheat 



/303 /3/0 /9// /3/2 A\/£r/?^G£r 




Fig. 9.— Graphs showing the average percentage of moisture in the first 6 feet of soil at the begiiming, 
' in the middle, and at the end of the fallow season, as foimd in the summer-cultivation tests of fall- 
plowed fallow at the Nephi substation, 1909 to 1912, inclusive. 

in 1911 and were left in stubble during the winter. They were plowed 
uniformly as soon as possible the next spring. One was then culti- 
vated normally during the summer of 1912, while the other was not 
cultivated. There were practically no weeds or volunteer grain on 



20 BULLETIN 157^ U. S. DEPARTMENT OF AGEICULTUKE. 



either plat, but whatever growth appeared on the cultivated plat 
was destroyed, while on the uncultivated plat it was allowed to remain 
but not to mature. Both plats were seeded uniformly in the fall 
of 1912 and they were treated ahke during 1913. Two alternate 
plats were added to the test in 1912. 

Soil samples were taken from the fallow plats, and moisture deter- 
minations were made. These showed no appreciable difference in the 
moisture content of the plats in either the individual foot sections 
or the 6-foot averages. There was a uniform decline in the moisture 
content of the plats from spring to seeding time in the fall. The 



20 



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Fig. 10.— Graphs comparing the average percentage of moisture in each of the upper 6 feet of soil at 
the beginning, in the middle, and at the end of the fallow season, as found in the summer-ctiltivation 
tests of fall-plowed fallow at the Nephi substation, 1909 to 1912, inclusive. 

yield of the plats m 1913, 11.9 and 9.5 bushels per acre, shghtly 
favored the noncultivated plat, but there was so much wmterkilling 
on both that the yields are not significant. 

The value of these tests was increased in 1912 by the addition of 
nine other plats, treated as follows: Two plats, light cultivation; two 
plats, medium cultivation; two plats, heavy cultivation; and three 
plats, no cultivation. 

These nine plats will be kept free from all vegetative growth. The 
noncultivated plats will be weeded with the least possible disturbance 
of the soil, thus affording an opportunity to study the value of cul- 
tivation methods for moisture conservation alone and not in connec- 
tion with weed eradication. 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI^ UTAH. 21 



SEEDING WINTER CEREALS. 

Four important factors related to the seeding of winter cereals, 
namely, the time, depth, method, and rate of seeding, have been 
rather extensively considered in the experimental work of the Nephi 
substation since its beginning. All these factors are interrelated and 
are so regarded in ordinary farm practice, but at Nephi each has been 



CU^mrED A/ORMALLK NOT CULT/l/ATEa 




Fig. 11.— Graphs showing the average seasonal decline in percentage of moisture in each of the upper 
6 feet of soil, as found in the summer-cultivation tests of faU-plowed fallow at the Nephi substation, 
1909 to 1912, inclusive. 

considered apart from the others arbitrarily, and the results are so 
presented herein. 

Time op Seeding Winter Cereals. 

WHEAT. 

The experiments dealing with the time of seeding winter wheat 
have been in progress since 1903. During that time winter wheat 
has been sown each year at a uniform rate of 3 pecks to the acre on 



22 BULLETIN 157, U. S. DEPARTMENT OF AGKICULTUEE. 



each of the following dates: August 15, September 1, September 15, 
October 1, October 15, and November 1. In the years from 1904 to 
1907, inclusive, the variety used was the Odessa (C. I. No. 3274). 
This variety was replaced by the Koffoid (C. I. No. 2997) in 1908 
and 1909. From 1910 to 1913 both the Koffoid and the Turkey 
(C. 1. No. 2998) have been used. Table VIII shows the average 
yields for the 6 years from 1904 to 1909, inclusive; the annual and 
average yields for both varieties for the 4 years from 1910 to 1913, 
inclusive; and the average yields for the entire 10-year period for 




X /3.0 

Fig. 12. — Diagram comparing the anmial and average yields obtained in the summer-cultivation 
tests of fall-plowed fallow at the Nephi substation, 1910 to 1913, inclusive. 

each of the six dates upon which the grain was sown. The average 
yields for the 10-year period are presented graphically in figure 13. 

Table VIII. — Annual and average yields of two iwieties of winter wheat for the years 
1910 to 1913, showing also the average yields of one variety for the years 1904 to 1909, 
and of all varieties for the years 1904 to 1913, inclusive, in date-of-seeding tests at the 
Nephi substation. 



Yield per acre of grain (bushels). 





Annual yields. 


Average yields. 


Date seeded. 




























1910 


1911 


1912 


1913 


1910-1913 




























1904^ 


1904-1913, 
























1909,1 one 


all 




Kof- 


Tur- 


Kof- 


Tur- 


Kof- 


Tur- 


Kof- 


Tur- 


Kof- 


Tur- 


variety. 


varieties. 




foid. 


key. 


foid. 


key. 


foid. 


key. 


foid. 


key. 


foid. 


key. 




Aug. 15 


15.60 


27. 30 


21.70 


23.50 


13. .50 


13.40 


Failure. 


1.70 


12. 70 


16.48 


17.95 


16. 61 


Sept. 1 


32.20 


36.80 


17. 80 


28.60 


6.30 


5.30 


0. 67 


6.83 


14.24 


19.38 


20. 32 


IS. 92 


Sept. 15 


12. 20 


20. 80 


33.80 


36. 50 


9.40 


7.70 


2. 67 


10.83 


14. 52 


18. 96 


15. 99 


16.29 


Oct. 1 


9.50 


13.50 


29.90 


26.40 


17.80 


15.90 


3.00 


10.67 


15.05 


16.62 


22.00 


19.53 


Oct. 15 


11.70 


16.00 


22. 50 


6. 00 


15.70 


7. 30 


1.17 


8.83 


12. 77 


9. 53 


22. 68 


18. 07 


Nov. 1 


14.20 


17. 80 


..20 


10. 00 


4. 20 


7.30 


(^) 


(2) 


9.20 


11.70 


20.46 


17.12 



1 The average yields for the six years from 1904 to 1909 presented herewere taken from Circular 61, Bureau 
of Plant Industry, U. S. Department of Agriculture, in which they were presented in connection with the 
annual yields for the same period. 

2 Not sown, because of stormy weather. 



TILLAGE AND KOTATION EXPERIMENTS AT NEPHI, UTAH. 23 



The results presented in Table VIII show no correlation between 
time of seeding and yield. Early seeding has given the best results 
in some years, while in others the best yields have come from late 
seeding, especially those in October. It will be observed, however, 
that as a rule the best yields have come from seeding between Sep- 
tember 1 and October 15. 



SOIL MOISTUKE AT SEEDING TIME. 



Beginning in the fall of 1908, the plats used in the time-of -seeding 
test were sampled to a depth of 6 feet just prior to the seeding of the 
plats. In the later years, when two varieties were sown, composite 
samples of both plats were taken. The percentages of moisture in 



2 ^ e & /o /2 _ 



20 



AUG. 15 

S£pr. / I 

S£PT/5 
OCT. / 
OCT./5 



mm . 



/6.e 



\/6.3 



\/S.9\ 



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Fig. 13.— Diagram comparing the 10-year average yields of winter wheat obtained in the time-of- 
seeding tests at the Nephi substation, 1904 to 1913, inclusive. 

each foot of soil at seeding time as shown by these samples are given 
in Table IX. 



Table IX. — Annual and average percentages of moisture in each of the first 6 feet of soil 
at different dates of seeding at the Nephi substation, for the years 1908 to 1912, inclusive. 



Dato of seeding. 


Depth of 
sampling. 


1908 1 


1909 


1910 


1911 


1912 


Average. 




f 1 


16.40 


14.60 


12.85 


12.67 


13.65 


14.03 




2 


17.30 


19.05 


17.44 


15.55 


17. 75 


17.42 


Aug. 15 


3 


14.12 


17.10 


16. 12 


10. 87 


14. 48 


14. 54 


4 


12. 45 


18. 30 


17.33 


10.84 


12.40 


14.26 


1 


5 


12.95 


20.60 


18.25 


12.24 


9. 88 


14. 78 




6 


12.37 


18. 15 


17.20 


14. 48 


11.60 


14. 76 


Average 




14. 26 


17.96 


16.53 


12. 78 


13.29 


14. 96 




f 1 


15.95 


17.30 


14. 73 


11.60 


15.65 


15. 05 




2 


18.10 


18. 30 


17.33 


15. 04 


18.83 


17.52 


Sept. 1 


3 


15.35 


17.75 


16.28 


11.80 


15.87 


15. 41 


4 


10.70 


19.45 


17.05 


10.75 


12.03 


14.00 




5 


9. 75 


17. 75 


•16.60 


8. 01 


10.60 


12. 52 




6 


10. 82 


18.30 


19.15 


9.08 


13.12 


14. 09 


Average 




13.44 


18.14 


16. 84 


11.05 


14. 35 


14. 76 








f 1 


16.32 


17.45 


12.10 


9. 97 


11.91 


13.55 




2 


16.70 


18. 75 


17. 38 


12. 53 


16. 69 


16. 41 


Sept. 15 


3 


14. 92 


17.00 


16.53 


11.20 


15.24 


14. 98 


4 


10. 22 


17. 55 


17.45 


12.44 


13.09 


14.15 




5 


10. 57 


16.85 


16.22 


11.93 


9.23 


12. 96 




6 


11.45 


17. 40 


17.65 


11.00 


10. 61 


13.62 


Average 




13. .36 


17.50 


16.22 


11.51 


12. 80 


14.28 







1 One plat only. In each of the other years the figures given are the average of two plats. 



24 



BULLETIN 157, U. S. DEPARTMENT OF AGKICULTUBE. 



Table IX. — Annual and average percentages of moisture in each of the first 6 feet of soil 
at different dates of seeding at the Nephi substation, for the yeans 1908 to 1912, inclu- 
sive — Continued . 



Date of seeding. 


Depth, of 

TTTnl in cr 


19081 


1909 


1910 


1911 


1912 


Average. 




f 1 


20. 00 


15. 60 


12.88 


13.47 


12. 55 


14.90 




2 


19.40 


18. 90 


16.43 


16.07 


17.00 


17.56 


Oct. 1 


3 


15. 55 


16.00 


16.58 


14. 98 


14. 49 


15.52 




4 


11.27 


17.90 


16. 78 


15.24 


13. 17 


14.87 




5 


10. 77 


16. 70 


18. 38 


14. 34 


13. 57 


14. 75 




6 


12.72 


17.05 


16. 33 


14.23 


13.37 


14.74 


Average 




14. 95 


17. 02 


16.23 


14. 72 


14. 03 


15.39 








f 1 


16.90 


15.35 


14.61 


12.29 


17.87 


15.40 




2 


18.60 


17.75 


16.80 


14. 98 


18. 59 


17.34 


Oct. 15 


3 


15.35 


16. 55 


16.65 


14.63 


17.40 


16.12 


4 


14. 10 


16 05 


16. 33 


13. 57 


15. 92 


15 19 




5 


1L08 


16!65 


16^28 


I'llSo 


13! 75 


13^94 




6 


10. 92 


17. 75 


18.00 


13.14 


15.45 


15.05 


Average 




14.49 


16.68 


16.44 


13.44 


16.50 


15. 51 










f 1 


18.55 


13. 95 


17.85 


14.68 




f 16. 26 




2 


20. 52 


17.35 


18. 78 


18. 02 


1 


18.67 


Nov. 1 


3 


19.72 


16.20 


18. 30 


14. 60 




17. 21 


4 


13.90 


13.95 


17.63 


11.25 




14. 18 




5 


11.15 


14.15 


17.05 


8. 97 


1 (2) 


1^.83 




6 


10.37 


14. 50 


16.55 


15. 49 




14.23 


Average 




15.70 


15.02 


17.69 


13.84 




15.56 









1 One plat only. In each of the other years the figures given are the average of two plats. 

2 Stormy weather prevented the sampling and seeding of these plats. 



It will be noticed in Table IX that there was no great difference in 
the average moisture content of the plats. The surface foot, usually 
very dry in the first few inches, varied in moisture content to some 
extent, owing partly to rainfall, but even in this foot the variation is 
within the hmits of experimental error. Moisture in the fii'st foot of 
soil is of chief importance at seeding time, because it is here that the 
plant starts hf e, and for this reason some relation between the moisture 
content of the first foot of soil at seeding time and the 5n.eld of the 
crop might be expected. . This relation failed to appear, however, in 
any one year. That it was not apparent in an average for the four 
years from 1909 to 1912 is shown in figure 14, in which the average 
moisture content of the first foot of soil on the six different dates of 
seeding, and the average yields of two varieties of winter wheat seeded 
on those dates are graphically presented. 

Figure 14 shows an apparent relationship between the moisture 
content of the first foot of soil and the yields of the plats seeded 
on the two earher dates, but for later dates the curves rxm almost 
parallel to each other. A discussion of the physical factors influenc- 
ing the time of seeding will aid in explaining this condition. 

FACTORS rNTLUENCING THE TIME OF SEEDING. 

On the dry lands of the Great Basin the best time for seeding 
winter wheat is greatly hmited by chmatic conditions. The long, 
dry summers exhaust the moisture of the fallow soil nearly to the 
depth to which the land is plowed, leaving the surface soil almost 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 25 



dusty to a depth of 4 to 8 inches, 
continued lack of rainfall, often 
until very late in the fall, sometimes 
to sow in order to have 
the seed in the groimd 
before snow falls. It 
is impracticable to sow 
seed in the dry soil, be- 
cause it would not ger- 
minate until rain fell, 
and then, if the storms 
brought insufficient 
moisture for continued 
growth, the plant very 
hkely would die after 
sprouting. This makes 
earlv seeding: in drv soil 



This condition, combined with 
prevents the sowing of wheat 
until farmers are compelled 



20 



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\ 

precarious. Farmers, l^j 
reaUzing this fact, sel- ^ 



dom seed ' ' in the dust , ' ' 
although good yields 
have sometimes been 
obtained from such 
seeding when it is 'fol- 
lowed by sufficient 
moisture for germina- 
tion and continued 
growth. 

It is almost impos- 
sible to place the seed 
below the dry soil, and, 
if it were possible, it is 
not practicable, b e - 
cause small seeds 
placed so deep often 
have difficulty in get- 
ting their first leaves 
to the surface. These 
facts explain why 
farmers generally wait 
for rain to wet the sur- 
face soil before thev 



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Fig. 14. — Graph showing the average percentage of moistiire in the 
first foot of soil at seeding time in the fall and the average yields 
of two varieties of winter wheat used in the time-of-seeding tests 
at the Nephi substation, 1909 to 1913, inclusive. 

sow their wheat. In 

order to obtain the highest yields from winter wheat in the Great Basin, 
however, it is essential that the plants make at least a fair growth before 
winter begins. To get the desired growth, the seed should be sown 



26 BULLETIN 157, U. S. DEPARTMENT OF AGRICULTURE. 

not later than October 1. When seeding is delayed until very late 
in the fall there is great danger of injury to the young plants if 
germination occurs, from what may be termed ''fall killing." They 
are in a very critical condition when freezing weather arrives. An 
open winter following this injury results in almost total failure of 
the crop, regardless of the tillage methods used in preparing the 
land and of the amount of moisture stored in it. 

As practical examples of the points brought out in the preceding 
discussion, the past four seasons, 1909-10 to 1912-13, are worthy 
of consideration. The seedings on August 15 and September 1, 
1909, were made when, owing to recent rains, there was plenty of 
moisture in the first foot to cause good growth. The yields of these 
plats in 1910 were high in comparison with those of the plats sown 
later, when the weather was dry and cold. The seedings on Sep- 
tember 15, 1910, were made under conditions similar to those in 
August, 1909. The yields on these plats were higher than those 
seeded ''in the dust" in August and those sown late in October. 
In the fall of 1911 and again in 1912 the weather was dry until 
early October, after which time there was plenty of moisture, but 
the weather was cold. As a result of these conditions the yields 
of both early-sown and late-soT^ni crops were low. Figure 15 shows 
the relation of precipitation to yield in this instance. The black- 
ened portions of the figure illustrate the daily precipitation from 
August 1 to November 30, inclusive, and the curves represent the 
yields in bushels per acre of the two varieties of wheat seeded on 
different dates during these months. 

It wiU be seen that early seeding if done in wet weather gave 
high yields, while it gave low yields, and sometimes almost failures, 
when done in dry weather. It is also sho^vn that late seeding, even 
when there was plenty of moisture, often resulted in serious loss 
because of injury to the tender plants by freezing. There seems 
to hav^e been some difference in the effect of these climatic condi- 
tions on the two varieties. This may have been due to a difference 
in the time of germination between the hard (Turkey) variety and 
the soft (Koffoid) variety. The writer is of the opinion that this 
difference in germination is largely responsible for the differences in 
yield. The soft wheat seems to germmate more rapidly than the 
hard wheat, and for this reason it is more advanced on a given date 
than the latter variety. This may not always be advantageous to 
it, as it may be in a tender stage of growth when drought or cold 
weather strikes it, and thus it may be injured more than the un- 
germinated seed of the hard variety. On the other hand, the soft 
wheat may be sufficiently far advanced to protect it from injury, 
while the slower germinating Turkey wheat may be stiU in a tender 
stage of growth. 



TILLAGE AND EOTATION EXPEEIMENTS AT NEPHI, UTAH. 



27 



The climatic and soil conditions under which these results were 



/lUGUST 



SE/1SO/V /309-/3/0. 

SEPTEMBEP OCTOBER A/Ol/EMBE/? 













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30 
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Fig. 15.— Diagrams showing the precipitation at seeding time in the fall and ciirves showing the annual 
yields of two varieties of winter wheat used in the time-of-seeding tests at the Nephi substation, 
1909 to 1913, inclusive. 



obtained present problems of a different nature than those so far 



28 BULLETIN 157, U. S. DEPAETMEXT OF AGRICULTURE. 

studied. Early seeding; not later than October 1, seems desirable, 
but as this is not always practicable, owing to a dry seed bed, the 
chief problem seems to be a mechanical one involving some im- 
provement of the machinery now used in seeding the grain. The 
improvement beheved to be necessary comprises a means for open- 
ing a furrow through the dry surface soil, sowing the seed in moist 
earth at the bottom of the furrow, and leaving the furrow partly 
open so that the plants will not have to force their way through 
several inches of dry soil. It is beheved that seed could be sown 
with good results in dry weather by this method, as the seed would 
germinate rapidly and a good stand of grain would be established 
before winter, thus greatly increasing the possibilities of a good crop. 

BARLEY, OATS, AND EMMER. 

In the fall of 1911 date-of-seedmg tests with winter barley, winter 
oats, and winter emmer were begun. Four dates were used for each 
grain, namely, September 1, September 15, October 1, and October 
15. All grains were so^va at the rate of 6 pecks per acre on the ^ 'oats " 
side of the drill. As has already been explained in connection with 
the discussion of the time of seeding winter wheat, there was much 
winterkilling in the seasons of 1911-12 and 1912-13, and, conse- 
quently, the results obtained from these experiments with barley, 
oats, and emmer are of little value. The tests are being continued, 
however. 

Depth of Seeding Winter Cereals. 

Depth-of-seeding tests with winter wheat have been in progress 
since the fall of 1908, while similar tests with winter barley, winter 
oats, and winter emmer were begun in 1911. In all the tests, seed 
has been sown at three different depths, 1.5, 3, and 6 inches, the 
drill being set in the first, second, or third notch, according to the 
depth desired. In all respects other than depth of seeding, the plats 
in each test were treated uniformly. 

Each fall the plats were seeded at what was considered the best 
time. Sometimes, as in 1909 and 1910, it was possible to sow the 
seed early enough to obtain a fair gi'owth before winter and, as a re- 
sult, good yields were obtained. On the other hand, as in 1908, 1911, 
and 1912, seeding was not possible until very late in the season, 
resulting in poor yields, for reasons already explained. 

The yields of winter barley, oats, and emmer were so small in 1912 
and 1913, because of late seeding and subsequent freezing, that they 
are not dependable and need not be presented here. The yields of 
winter wheat in 1913 also were very small, but as they are important 
in connection with the results of the preceding four years, the yields 
for the five years are presented in Table X. 



TILLAGE AND ROTATION EXPEEIMENTS AT NEPHI^ UTAH. 29 



Table X. — Annual and average yields of winter wheat sown at different depths at the 
Nephi substation, for the years 1909 to 1913, inclusive.'^ 



Deptti planted. 


Yield per acre of grain (bushels). 


1909 


1910 


1911 


1912 


1913 


Average. 


About 1.5 mches (drill in first notch) 

About 3 inches (drill in second notch) 

About 6 inches (drill in third notch) 


4. 30 
2 4.07 
2. 10 


20. 20 
16.-60 
15 


27.70 
28. 50 
27.20 


16. 30 
16. 30 
19.10 


3.20 

2 

2 


14. 34 
13.49 
13.08 



1 The Koffoid variety (C. I. No. 2997) was used in 1909, while Turkey (C. I. No. 2998) was used from 
1910 to 1913, inclusive. 

2 Average yield of sev6n check plats. 



The results of five years as recorded in Table X show very little 
difference in the average yield of winter wheat seeded at different 
depths. The yields of 1910, a good season, favored shallow seeding. 
Those of 1911, a better season, showed a slight advantage in favor 
of a medium depth of seeding. In fact, it seems that depth of seed- 
ing is less important than time of seeding, which, as has been 
sho^vn, is governed at present by soil and climatic conditions. 

Method of Seeding Winter Wheat. 

Tests designed to determine the relative value of broadcasting, 
ordinary drilling, and cross drilling have been carried on at Nephi 
for several years. After what has been said concerning the soil and 
chmatic conditions which usually obtain at seeding time in the fall, 
it is easy to see why broadcasting has been not nearly so successful 
as drilling. The broadcast plats have been practically failures each 
season that method of seeding has been tested, while the drilled plats 
yielded from 20 to 25 bushels per acre. 

On the cross-drilled plats the drill was first drawn lengthwise 
and then crosswise of the plat. On one plat the usual rate of seed- 
ing, 3 pecks per acre, was used, while on the other twice the usual 
rate, or 6 pecks per acre, was used. In the one case the drill was 
set to sow at the rate of 1.5 pecks to the acre and in the other at the 
rate of 3 pecks, the cross drilling making the quantities sown double 
those just mentioned. Near these two plats there was always one 
seeded in the usual manner at 3 pecks per acre. This plat, bemg 
usually a check plat, was not always seeded at the same time as the 
others, however, and so its yields are not strictly comparable with 
those of the cross-drilled plats. All are presented, however, m Table 
XI, which gives the annual and average yields for the five years from 
1909 to 1913, inclusive. 



30 



BULLETIN 157, U. S. DEPARTMENT OF AGEICULTURE. 



Table XI. — Anntuil and average yields of winter wheat drilled in the ordinary manner 
and cross drilled at the Nephi substation, for the years 1909 to 1913, inclusive.^ 



Method and rate of drilling. 



Yield per acre of grain (bushels). 



1909 



1910 



1911 



1912 



1913 



Average. 



5 years. 4 years. 



Ordiaary drilling at 3 pecks per acre ^4.07 

Cross drilling, 1.5 pecks per acre each way 3. 50 

Cross driUiag, 3 pecks per acre each way i 



16.60 22.30 
18.50 ' 26.70 
17.80 28.80 



16.30 
17. 10 
17.60 



5. 17 
6.00 
5.34 



12.89 
14.36 



15.09 
17.08 
17.39 



1 The KofEoid variety was used in 1909, while the Turkey was used from 1910 to 1913, inclusive. 

2 Average of seven check plats. 

Table XI shows that the difference between the yields of the cross- 
drilled plats and those drilled in the ordinary manner, both seeded at 
the rate of 3 pecks per acre, is very small, almost insignificant when 
the comparative cost of seeding is considered. It is not known 
whether the difference in yield favoring the cross-drilled plats is 
caused by cross drilling or by a possible increase in the rate of seed- 
ing which may have occurred owing to the double seeding, i. e., the 
drill may have seeded more than 3 pecks when set to sow 1.5 pecks 
each way of the plat. It is believed that the increase in the rate of 
seeding is responsible for the higher yield of the plats seeded at 6 
pecks per acre, since these results agree with those of the rate-of- 
seeding tests with winter wheat. 

Rate of Seeding Winter Wheat. 

Rate-of-seeding tests with wdnter wheat were conducted at Nephi 
for the three years from 1909 to 1911, inclusive, and they were 
repeated in 1913. There was no test of this kind in 1912. In each 
year six different rates of seeding were used, namely, 2, 2.5, 3, 4, 5, 
and 6 pecks per acre. All plats in the test were treated uniformly in 
every way except as to the rate of seeding. The annual and average 
yields in bushels per acre obtained are presented in Table XII. 

Table XII. — Annual and average yields of winter wheat in the rate-of-seeding test at the 
Nephi substation in 1909, 1910, 1911, and 1913} 



Rate of seeding per acre. 



Yield per acre of grain (bushels). 



1909 



1910 



1911 



1913 



Average. 



4 years. 



3 years 
(1910, 1911. 
and 1913). 



2 pecks 

2.5 pecks 

3 pecks (ordinary) . 

4 pecks 

5 pecks 

6 pecks 



4. 80 
2.33 



16.00 
15.30 
19. 30 
19.30 
19.30 
17.00 



23.50 
28. 50 
21.30 
28. 70 
33.70 
30. 30 



Failiu-e. 

Failure. 
2.67 
3.00 
2.83 
3.00 



10.92 



14.69 
15. 16 
13. 16 



13. 17 
14.60 
14.42 
17.00 
18. 61 
16. 77 



The KofEoid variety was used in 1909, while the Turkey was used in 1910, 1911, and 1913. 



TILLAGE AXD ROTATION EXPERIMENTS AT NEPHI^ UTAH. 31 

The principal fact brought out by Table XII is that the higher 
rates of seeding have given the largest average yields. This is rather 
contrary to the belief of dry-land farmers in the Great Basin, who 
fear that heavier seeding than 3 pecks to the acre would be disastrous 
to the crop in extremely dry seasons. That this view is not well 
founded is shown by the fact that in 1910 and 1911, the two driest 
years at Nephi since 1898, the highest rates of seeding gave yields as 
high as, or much higher than, the lower rates. The results available 
indicate that a 4-peck or o-peck rate is the most profitable. 

It is likely that 3 pecks per acre would be sufficient if all seeds sown 
produced plants that matured, but it has been found at Nephi that 
the average vvdnter survival among fall-sown cereals is about 65 per 



O 2 4 6 e /O /2 /■<' /6 /a 20 22 24 ^ 28 




Fig. 16.— Diagram comparing the amiual and average yields obtained in the spring-cultivation tests 
of winter wheat at the Nephi substation, 1909 to 1913, inclusive. 



cent,^ in which case only about 30 pounds of the seed produce plants 
that mature. 

SPRING CULTIVATION OF WINTER WHEAT. 

Two adjacent plats have been used each year since 1909 for testing 
the value of spring cultivation of winter wheat compared with no 
cultivation. These plats were treated uniformly in every other 
respect. Normal cultivation consists of harrowing the crop, usually 
with a spike-toothed harrow, as early in the spring as advisable, 
repeating this operation, if necessary, before the plants are in boot. 

The chief value of spring cultivation, it was thought, would be 
found in its favorable influence upon the yield of the crop by breaking 
the crust which usually forms upon the surface of the ground during 
the winter and early spring. The destruction of this crust was 



1 Cardon, P. V. Cereal investigations at the Nephi substation. U. S. Dept. Agr. Bui. 3i. p. 34, 1013. 



32 BULLETIN 157^ U. S. DEPARTMENT OF AGRICULTURE. 

expected to create a mulch which would prevent the evaporation of 
soil moisture and allow the plant greater freedom for growth. These 
factors constitute the basis of a great deal of argument in favor of 
the spring cultivation of winter wheat, a practice which is rather gen- 
eral in the Great Basin area. The results obtained are quite contrary 
to those which were expected. 

YIELD OF GRAIN. 

The annual and average yields of the plats for 1909 to 1913, inclu- 
sive, are given in Table XIII and are shown graphically in figure 16. 



Table XIII. — Annual and average yields of winter wheat obtained from cultivated and 
uncultivated plats at the Nephi substation, for the years 1909 to 1913, inclusive} 



Treatment. 


Yield per acre of grain (bushels). 


1909 


1910 


1911 


1912 


1913 


Average. 


Cultivated. 


8. 33 
12.66 


19.00 
19. 50 


27.90 
27. 70 


14. 90 
14. 90 


9.83 
10.50 


15.99 
17. 05 


Not CTiltivated 





1 The Koffoid variety was used in 1909, while the Tvirkey was used in 1910 to 1913, inclusive. 



It is of peculiar interest to note that in four of the five years there 
has been practically no difference in the yields obtained in this test. 
The yield of the noncultivated plat has been higher in three of the 
five years, while in 1911 the difference of 0.2 of a bushel per acre 
favored the cultivated plat. The yields of 1912 were identical. The 
difference in the average yield of 1.06 bushels in favor of the noncul- 
tivated plat is largely due to the greater yield of this plat in 1909. 

EFFECT ON SOIL MOISTURE. 

Soil samples were taken each year from each of the plats, usually 
at the beginning, in the middle, and at the end of the season. Six- 
foot samples were taken, and the moisture content of each foot section 
was determined in the manner previously described in this bulletin. 
The results are presented in Table XIV, which shows the annual and 
average percentage of moisture in each foot and for the entire 6 feet 
in the spring, in the summer, and in the faU. 

Table XIV shows a marked uniformity in the moisture content of 
the two plats at the beginning, in the middle, and at the end of the 
season, the seasonal loss from both plats being about the same. The 
greatest difference was shown in 1909, when the cultivated plat with 
a thin stand of grain lost moisture less rapidly than the noncultivated 
plat, on which the stand was thicker. In aU other years the stands 
were more nearly alike. Figures 17, 18, and 19 illustrate graphically 
the results shown in Table XIV. It is apparent that spring cultiva- 
tion of winter wheat did not conserve any appreciable amount of 



TILLAGE AND EOTATION EXPERIMENTS AT NEPHI, UTAH. 33 



moisture in the 6 feet of soil sampled and that, so far as moisture con- 
servation is concerned, no advantage was derived from the cultiva- 
tion of the crop. 



Table XIV. — Annual and average percentages of moisture in each of the first 6 feet of soil 
on the plats used in the test of spring cultivation of winter wheat at the Nephi substation, 
samples taken in spring, summer, and fall, for the years 1909 to 1913, inclusive. 









Depth of sampling. 








TrGstiii6iit fiiicl (l3.t6 of dctGrmi- 














Average. 


I13,tiOD, 
















1 foot. 


2 feet. 


3 feet. 


4 feet. 


5 feet. 


6 feet. 




CULTIVATED. 
















1909: 
















Jiuie 26 


12.60 


16. 25 


18.02 


18. 50 


19.25 


17. 63 


17.04 




12. 75 


15. 20 


15. 45 


18. 95 


16. 70 


12. 82 


15. 31 


1910: 


















13. 05 


16. 30 


17.33 


17. 70 


18. 15 


19. 95 


17.08 




10. 38 


12. 63 


11.33 


11.18 


13. 30 


16. 90 


12. 62 




8. 53 


11. 35 


11.10 


11.15 


13. 10 


11. 38 


11. 10 


1911: 


















18. 28 


21. 90 


20. 46 


18. 90 


17. 80 


15. 65 


18. 83 




9. 12 


12. 13 


11.95 


11.48 


14. 72 


13. 42 


12. 14 


1912: 


















20. 17 


21. 51 


20.17 


17.99 


15. 21 


17.04 


18. 68 




9. 92 


13. 11 


12.14 


14. 25 


15. 23 


16. 23 


13. 48 




9. 48 


13. 65 


12. 24 


11.52 


13. 99 


17. 30 


13. 03 


1913: 


















20. 50 


22. 22 


21.38 


18. 32 


15. 98 


15. 54 


18. 99 




10. 83 


15. 77 


15. 63 


15. 73 


15. 54 


15. 06 


14. 76 


September 6 


10. 67 


13. 49 


12. 24 


11.43 


13. 58 


12. 49 


12. 32 


• 


18. 00 


20. 48 


19. 84 


18. 23 


16. 79 


17. 05 


18. 40 


Average in summer 


10. 93 


14.44 


14.28 


14.92 


15. 83 


16. 46 


14.72 


Average in fall 


10.11 


13. 16 


12. 60 


12. 91 


14. 42 


13.48 


12. 78 


NOT CULTIVATED. 
















1909: 
















June 26 


13. 15 


16. 15 


17. 20 


17. 28 


16. 85 


15. 22 


15. 97 


August 12 


10!65 


12! 90 


12. 20 


10. 15 


11! 05 


13! 45 


11! 73 


1910: 


















14. 35 


17. 65 


18.95 


18. 20 


18. 35 


19. 45 


17. 82 


June 28 


12. 98 


11.83 


11.78 


11.05 


13. 20 


17. 95 


13. 13 


August G 


8. 75 


11.88 


11.65 


11.75 


13.10 


17. 85 


12.50 


1911: 
















April 26 


18.79 


22. 69 


21.79 


19. 60 


19.07 


17. 78 


39.95 


September 20 


8. 91 


13. 39 


13.08 


12. 51 


15. 13 


13. 25 


12. 71 


1912: 
















Mav 15 


16. 77 


21.35 


20. 21 


20. 22 


19. 21 


17. 20 


19. 16 


June 27 


12. 04 


14.15 


14. 05 


18. 00 


16.17 


15. 99 


15.07 


August 2 


iO.61 


13. 69 


12. 62 


12. 67 


14.78 


16.72 


13. 52 


1913: 
















Mav 17 


18.88 


20. 59 


20. 20 


19. 10 


17.12 


19.04 


19. 16 


June 20 


10. 73 


15.80 


17.21 


15. 91 


16. 23 


16. 05 


15.47 


September 6 


11,30 


12. 88 


12. 29 


12. 05 


15. 18 


13. 83 


12. 92 


Average in spring 


17.20 


20. 57 


20.29 


19. 28 


18. 44 ' 


18. 37 


19.02 


Average in summer 


12. 23 


14. 48 


15. 06 


15. 56 


15. 61 


16. 53 


14.91 


Average in fall 

• 


10. 04 


12. 95 


12. 37 


11.83 


13. 80 


15. 02 


12. 68 



EFFECT OF CULTIVATION ON THE PLANTS. 

As already stated, the spring cultivation of winter wheat was ex- 
pected to allow the plants greater freedom for development. It is 
not kno^vn to what extent this result obtained, but it is reasonable to 
beheve that the surface of the soil was placed in better condition for 
^ plant development than where the crust was left unbroken and the 
plants compelled to push through it. It is, however, almost impos- 
sible to break the crust without injuring some plants. Whether this 
injury is offset by the benefit to others is difficult to determine, 



34 BULLETIN 157, U. S. DEPARTMENT OF AGRICULTURE. 



though the yields of the past five years indicate that it is not. An 
effort was made in 1913 to determine the exact extent of the injury 
to the plants by harrowing with a spike-toothed harrow, the teeth of 
which were set almost perpendicularly. At this time there was a 
heavy crust on the ground, which the plants were penetrating with 
difficulty. 

On May 21, when the plants were from 3 to 4 inches high, four 
areas were staked off on plat 2 2D, and the plants in each area were 
counted before the plat was harrowed. Each area was 3.3 feet 
square, thus containing 40V0 of an acre, so that the total area of the 



>4 



is 















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V 

V 

















II 



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-\ — 
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\ \ 
\\ 




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^ — 




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VV— 




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\\ 




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£:X/=>1. ^/s^A T/Of^ 
CL/LT/\/AT£X> /UJffl^Z 



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Fig. 17. — Graphs showing the average percentage of moisture in the first 6 feet of soil at the beginning, 
in the middle, and at the end of the crop season, as found in the spring-cultivation tests of winter 
wheat at the Nephi substation, 1909 to 1913, inclusive. • 



four units equaled y^oo- s-cre. About one week after harrowing, 

the plants in each area were counted again and the loss due to har- 
rowing was determined. On the basis of the figures obtained, the 
stand was 218,000 plants per acre before and 193,000 plants per acre 
after harrowing, a loss of 25,000 plants, or 11.54 per cent. This loss 
alone would allow the plants greater freedom for development, and it 
might be expected to increase the number of culms per plant. 

To determine the effect of harrowing on the production of culms 
the total number per unit area was determined just before harvest 
and the average number of culms per plant calculated. The average 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. 



35 



number on the cultivated plat was 4.17, while on the uncultivated 
plat it was 4.05. The particular areas which were counted on the 
uncultivated plat, however, showed a thinner stand than those on 
the cultivated plat, so that the niunber of culms per plant does not 
show entirely the difference in development. The number of plants 
per acre on the uncultivated plat, as indicated by the areas counted, 
was 165,000 with a total of 663,000 culms. On the cultivated plat, 
the stand was 193,000 plants to the acre, with 805,000 culms, which 
was over 21 per cent more than on the uncultivated plat. On only 
one of the four uncultivated areas counted was the stand as thick as 
on the cultivated areas. On this area the average number of cuhns 



2/ 



20 



I" 

I 

I" 



SPP/A/6 S/1MPUA/G 



SUMMER S/IMPUA/G 



P/iLL S/1MPL/A/G 



/S 



/O 













1 




-s — 
\ ^ 






1 
11 
11 






N 

\ 




-t — 
/ 


















































































EXPA/^/VAbOA/- 















































































/ / 










1 
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2 S ^ 
DEPTH /A/ PEET 



6 / 



Fig. 18. — Graphs comparing the average percentage of moisture in each of the upper 6 feet of soil at 
the beginning, in the middle, and at the end of the crop season, as found in the spring-cultivation 
tests of winter wheat at the Nephi substation, 1909 to 1913, inclusive. 

per plant was 3.74. On a cultivated area, with practically the same 
stand, the niunber of culms per plant was 4.14, an increase of 11 per 
cent. 

On the same areas on the imcultivated plats the average yield per 
imit area 3.3 feet square was 156 grams of straw and 103 grams of 
grain. On the areas in the cultivated plats the yields were 199 
grams of straw and 114 grams of grain. These figures indicate that 
cultivation caused a marked increase (27.6 per cent) in yield of straw, 
but a much smaller increase (10.7 per cent) in yield of grain. The 
yields obtained on the unit areas are contradictory to those from the 
entire plats, as shown in Table XIV, which shows a decrease in yield 
on the cultivated plat of 6.4 per cent. 



36 BULLETIN 157^ U. S. DEPARTMENT OF AGEICULTUEE. 



TIME OF HARVESTING WINTER WHEAT. 

During the period from 1909 to 1912, inclusive, a test of the effect 
of the time of harvesting upon the yield and quahty of winter wheat 
was conducted. The milling and chemical tests of the wheat were 
made by the division of chemistry of the Utah station, but the data 
are not available at this time. Only the data on yield will be pre- 
sented here. 




A/or COLTTV/ITED. 



I 3UA7AfEf? 77 

F-/\LL 

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/ 













> 

— / 








/ 

/ 

/ 

/ — 


/ 






> 
/ 
/ 




-Hi 

i 1 






--/— 
/ 
/ 
/ 




— 1- 
1 
1 

-4 










/ 
/ 











/ 



2 3^S6/23^S6 
OaPT/-/ //V FETETT. 

Fig. 19.— Graphs showing the average seasonal decline in the percentage of moisture in each of the 
upper 6 feet of soil, as foxind in the spring-cultivation tests of winter wheat at the Nephi substation, 
1909 to 1913, inclusive. 

The four plats used in this test lay side by side and were treated 
uniformly up to and subsequent to the time of harvesting. One of 
these plats was harvested when the kernel was in the green-dough 
stage and one each week thereafter until all were harvested. In this 
way the grain was cut in four different stages of maturity, namely, 
green dough, hard dough, fully ripe, and overripe. The annual and 
average yields of the plats for the four years are given in Table XV. 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI^ UTAH. 37 



Table XV. — Annual and average yields of luinter wheat harvested at four different stages 
of maturity at the Nephi substation, for the years 1909 to 1912, inclusive. 





Yield per acre of grain (bushels). 


Stage of maturity when harvested. 














1909 


1910 


1911 


1912 


Average. 




7.83 


8.80 


20.30 


6.50 


10.86 




8.83 


14.00 


26.40 


10.20 


14.86 




6.33 


13.80 


24.60 


11.50 


14.06 




8.50 


12.70 


20. 70 


11.80 


13.43 



Table XV shows that with one exception the yield each year 
favored har\^esting in the hard-dough stage, though the differences 
are not great. The earliest harvest gave the smallest yields, due 
probably to the shrinking of the grain. The small decrease in the 
average yield from hard dough to overripe was probably due to 
shattering at harvest time. 

FREQUENCY OF CROPPING LAND TO WINTER WHEAT. 

One of the first tests begun by the Utah experiment station on the 
Nephi farm was planned to determine the relative return from 
cropping land to winter wheat continuously, every second year, one 
year in three, and two years in three. This test was conducted on 
four fifth-acre plats until the fall of 1907, when five tenth-acre plats 
were added, to allow the production of a crop under each condition 
each year. Since 1907, then, nine plats have been used. 

The total yields per acre of the four fifth-acre plats obtained pre- 
vious to 1908, the annual and total acre yields of all the plats from 
1908 to 1913, and the total yields of the fifth-acre plats from 1904 to 
1913, inclusive, are reported in Table XVI. 

Table XVI. — Annual and total yields of winter wheat obtained from continuous and 
alternate cropping and from growing one and two crops in three years at the Nephi 
substation, 1904 to 1913, inclusive. 



Yield p^r acre of grain (bushels). 



Frequency of 
crop. 


Total 
yield, 
1904 to 
1907.1 


1908 


1909 


1910 


1911 


1912 


1913 


Total, 
1908 to 
1913. 


Total, 
1904 to 
1913. 


Continuous 

Alternate .... 

Do 


60.20 
50. 80 


13.41 
32. 66 
FaUow. 

32. 74 
Fallow. 
2L 16 

FaUow. 
Fallow. 
19. 16 


14. 58 
Fallow. 
2.50 

13. 42 
2. 50 
FaUow. 

Fallow. 

3.50 
FaUow. 


7. 80 
9.90 
FaUow. 

FaUow. 
10.30 
8.20 

5.00 
Fallow. 
Fallow. 


5. 70' 
Fallow. 
28.00 

23.60 
FaUow. 
8. 10 

Fallow. 
Fallow. 
27. 00 


6. 00 
4. 80 
Fallow. 

3.90 
6.50 
FaUow. 

Fallow. 

10. 80 
FaUow. 


4.50 
FaUow. 
1.83 

FaUow. 
6. 83 
2.33 

11. 17 
FaUow. 
Fallow. 


51. 99 
47.36 
32. 33 

73. 66 
26. 13 
39. 79 

16. 17 
14.30 
46. 16 


112. 19 
98. 16 


Two crops in 

three years 

Do 


25. 10 


98. 76 


Do 






One crop m three 

years. 

Do 


49. 10 


65.27 


Do 













1 Taken from Bulletin 112 of the Utah Agricultural Experiment Station. 



38 BULLETIN 157, U. S. DEPAKTMENT OF AGRICULTURE. 



The data presented in Table XVI are not wholly dependable, prin- 
cipally because winterkilling so reduced the yields in some years 
that their comparative value was almost wholly lost. The volunteer 
crops on the continuously cropped plat and the plat cropped two 
years in three were less affected by winterkilling than the sown 
crops, for the reason that they made more growth in the fall. As a 
result, uncontrollable factors, such as thin stands, weeds, etc., 
caused wide variations in the results, which did not indicate the 
true value of the methods employed. 

The continuously cropped plat has not failed completely, however, 
in any year, even in the very dry years 1910 and 1911. In 1911, 
when there was very little winterkilHng and good gro^dng conditions 
prevailed, the continuously cropped plat and that cropped two years 



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Fig. 20.— Graphs compariBg the average percentage of moisture in each of the upper 10 feet of soil at 
the beginning of each season, as found on the alternately cropped and continuously cropped plats 
at the Nephi substation, 1909 to 1912, inclusive. 

in three fell far below the others in yield. Under favorable condi- 
tions, it appears that the plats that have been faUow one or two 
years will give the best results. So much depends upon the time 
of planting, winterkilHng, etc., however, that continuous cropping 
sometimes appears to be profitable, owing to the survival of volun- 
teer grain. 

The severe winterkilling in some years completely offsets the 
advantage of some plats in high soil-moisture content. This is weU 
illustrated by figure 20, from which it wiH be seen that in 1909 the 
difference in moisture content of the continuously cropped plat and 
the alternately cropped plat was greatly in favor of the latter at the 
beginning of the season, yet, because of a better stand, due to the 
volunteer grain, the continuously cropped plat yielded nearly seven 
times as much as the other, as is shown in Table XVI. In 1910 
the differences, though less marked, were much the same as those of 



TILLAGE AXD EOTATIOX EXPEEIMEXTS AT XEPHI, UTAH. 39 



the previous year. In 1911. however, under favorable conditions, 
the yields were consistent with the soil moisture. In 1912 there 
was httle difference either in moisture or yield. 

These results indicate that where a good stand is obtained in the fall 
and httle winterkilhng foUows, the crops following fallow will yield 
more than those grown on continuously cropped land. To determine 
the relative value of the two systems of cropping, the cost of growing 
a crop and of maintaining a fallow must also be taken into consid- 
eration. In the vicinity of Xephi, the cost of growing and harvest- 
ing wheat is about S3 per acre more than the cost of maintaining a 
fallow throughout the year. This extra cost must be charged 
against the crop which is obtained in alternate years on the con- 
tinuously cropped land. On this basis, the 14 bushels greater yield 
per acre m 10 years from the land continuously cropped have been 
obtamed at a cost of S15, for the S3 extra cost has been incurred 
five times in the 10 years. This extra cost is greater than the value 
of the increased yield, which is further evidence that alternate crop- 
ping and fallowing is preferable to continuous cropping to wheat. 

ENTERTILLED CROPS COMPARED W ITH FALLOW IN ALTERNATION WITH WINTER 

The most direct attempt made at the Nephi substation to find a 
successful substitute for the alternation of a cereal crop and summer 
faUow has been in a simple rotation in which winter wheat was 
grown after fallow and after corn, peas, and potatoes in rotation. 
As this test has been in progress since 190S sufficient data have been 
accumulated to justify consideration at this time. An outline of 
the rotation is given in Table XVII. 



Table XVII. — Rotation of intertilled crops and fallow alternating vnth wheat. 



Plat. 


190S 


1909 


1910 


1911 


1912 


1913 


12B 


Wheat. ... 
...do 


Fallow. . . . 
Com 


Wheat 

...do 


Fallow 

Peas 


'^Tieat.... 
...do 


FaUow. 
Potatoes. 
Peas. 
Com. 

Wheat. 
Do. 
Do. 
Do. 


13B 


14B 


...do 


Potaroes. . 
Peas 


...do 

...do 

Fallow 

Com 


Com 

Potatoes . . 

Wheat.... 
...do 


...do 

...do 

Fallow 

Peas 


15B 


...do 


12C 


Fallow. . . . 
Potatoes . 


Wheat 

...do 


13C 


140 


Peas 


...do 




...do 


Com 


15C 


Com 


...do 


Pppj? 


...do 


Potatoes . . 











TEEATMEXT OF PLATS. 

The four plats which had grown wheat were plowed in the fall of 
each year to a uniform depth of about S inches. The land then 
received no cultivation until the next spring, when it was double 
disked or harrowed sufficiently to destroy ah weeds and make a good 
faUow or a good seed bed. The plat to be summer-fallowed was 
treated normally in the spring and throughout the sum m er. The 



40 BULLETIN 157, U. S. DEPARTMENT OF AGEICULTUKE. 



corn, peas, and potatoes were planted in rows far enough apart to 
permit intertillage, the cultivation during the summer being prac- 
tically the same for the cropped and the fallow plats. The corn and 
peas were drilled in rows about 35 inches apart, while the potatoes 
were dropped behind a plow in hills 24 inches apart in rows 3 feet 
apart. 

After the crops were harvested from these plats in the usual manner 
in the fall, winter wheat was sown on them and on the fallow plat at 




Fig. 21— Graphs showing the average percentage of moisture in the first 6 feet of soil at the beginning 
and at the end of each season, as found in the rotation experiments at the Nephi substation, 1908 to 
1913, inclusive. 

the same rate and on the same date. The subsequent treatment of 
the plats was identical in every respect. 

MOISTURE CONTENT OF THE SOIL. 

Soil-moisture determinations were made on the plats in the rota- 
tion during each year of the test. The plats growing wheat were 
sampled at the beginning, in the middle, and at the end of each 
season, while the other plats were sampled about once a month during 
the season. The moisture content of each foot of soil to a depth of 
6 feet was determined in the usual manner. 

The results indicate that there was very httle difference in the 
moisture content of any foot of soil on the different plats. The varia- 



TILLAGE AND EOTATION EXPERIMENTS AT NEPHI, UTAH. 41 



tions favored one plat one year and another plat the next, changmg 
so frequently that no one plat had any marked advantage. The 
average moisture content in the first 6 feet of soil on all plats in the 
rotation at the beginning and end of each season from 1908 to 1913, 
inclusive, is shown graphically in figure 21. It will be noted that 
the average moisture content of the plats was usually surprisingly 
uniform, and that no great difference existed in any case. During 
the wheat years the moisture content of all plats was reduced to a 
minimum, but during the alternate years the moisture content re- 
mained reasonably constant. 



YIELDS OBTAINED. 



The 5delds of the various crops obtained in these rotation experi- 
ments are presented in Table XVIII. No attention should be paid to 
the yields of wheat from the '^B " plats in 1908, as they were occupied 
by four different varieties in the regular varietal test, and varietal 
differences probably affected the yields. In all other years the same 
variety was used on all plats. 

Table XVIII. — Yields obtained in tests of winter wheat ^ in alternation with fallow and 
with corn, peas, and potatoes in rotation at the Nephi substation, for the years 1908 to 1913, 
inclusive. 

[Yields per acre (wheat and potatoes in bushels, corn and peas in pounds).] 



Plat. 


1908 


1909 


1910 


Crop. 


Yield. 


Crop. 


Yield. 


Crop. 


Yield. 


12B 


Wheat 


27.50 
25.83 
30.16 
22. 66 


Fallow 




Wheat 


13.7 
19.3 
17.2 
18.3 


13B 


do 


Com (fodder). 
Potatoes 


1,240 
84.7 

1,050 
4. 66 
2. 50 

2.16 
6.50 


do 

do 

do 

Fallow 


14B 


do 


15B 


do 


Peas (vines)... 
Wheat 


120 


Fallow 


130 

14C 


Potatoes 

MS"- 


42.50*' 

1,080 
220 
630 
17.5 


do 

}....do 

}....do 


Com (fodder). 
Potatoes 


40 
7.35 

35 


150 


Peas (vines)... 







Plat. 


1911 


1912 


1913 


Crop. 


Yield. 


Crop. 


Yield. 


Crop. 


Yield. 


12B 


Fallow 




Wheat 


14.7 
17.8 

18.8 
18.7 


Fallow 




13B 


Peas 


Failure. 
40 

4 

30 

28.5 

32.1 
29.5 


do 


Potatoes 


34.5 

95 

20 

550 

200 
2.0 

4.2 

4.4 
4.2 


14B 


Com (fodder).. 
Potatoes 


do 


MS?r 


15B 


do 


[Fodder 

Com<UnsheIled 

1. grain 

Wheat 


12C 


Wheat 


Fallow 


13C 


do 


Com (fodder).. 
Potatoes 


225 
90 
1,420 
32.4 


}....do 


140 


do 


do 


15C 


do 


do..... 









1 In 1908 the wheat plats were a part of the regular varietal test, so that the results for that year should 
be disregarded. The varieties were as follows: On plat 12B, Crimean (C. I. No. 1433); plat 13B, Crimean 
(C. I. No. 1435); plat 14B, Crunean (C. I. No. 1436); and on plat 15B, Kofioid (C. I. No. 2997). In 1909 the 
last-named variety was grown on all plats, while in 1910 and succeeding years the Turkey variety (C. I. 
No. 2998) was used. 



42 BULLETIN 157^ U. S. DEPARTMENT OF AGRICULTUEE. 

Wheat after corn gave the highest yield obtained, in 1909, while 
wheat after fallow yielded better than wheat after either potatoes or 
peas. The yields of 1909, however, were extremely low because of 
excessive winterkilling. Consequently they would be practically 
worthless if they were not relatively the same as those obtained in 
later years. In 1910 wheat after fallow yielded much less than wheat 
after any intertilled crop. In 1911 wheat after potatoes gave the 
highest yield, while there was little difference in the yields of the other 
plats. Wheat after fallow again gave the lowest yield in 1912 and 
1913. A summary of the wheat yields obtained in this test for the 
five years from 1909 to 1913, inclusive, is given in Table XIX. 

Table XIX. — Annual and average yields of ivinter wheat obtained after corn, potatoes, 
peas, and fallow, at the Nephi substation , for the years 1909 to 1913, inclusive. 



Yield per acre of grain (bushels). 



Rotation. 
















1909 


1910 


1911 


1912 


1913 


Average. 


Wheat after com 


6. 50 


19. 30 


28. 50 


18. 80 


4. 40 


15.50 


Wheat after potatoes 


2. 50 


17. 20 


32. 10 


18. 70 


4. 20 


14.94 


Wheat after peas 

Wheat after fallow 


2.16 


18. 30 


29. SO 


17.80 


4.20 


14.39 


4.66 


13. 10 


30.00 


14.70 


2.00 


12.89 



Table XIX shows that the average yield of wheat for five years 
was less after fallow than after corn, potatoes, or peas. 

A summary of the total crop yields of all plats since the test began 
is given in Table XX, where it wiU be noticed that plats 12B and 
12C, wheat after fallow, have given the lowest total returns per acre. 

Table XX. — Summary of total crop yields from the intertillage and fallow rotation plats 
at the Nephi substation, 1908 to 1913, inclusive. 



Total yields per acre. 



Years and plats. 


Wheat. 


Com. 


Peas. 


Potatoes. 


Grain. 


Fodder. 


Seed. 


Hay. 


1909 to 1913: 

12B 


Bus. 
28. 40 
37. 10 
36.00 
37. 00 

36. 66 
35. 20 
38. 66 
40. 20 


Bus. 


Lbs. 


Lbs. 


Lbs. 


Bus. 


13B 


None. 
None. 
2.9 


1,240 
40 
550 


Failure. 

20 
None. 


Failure. 
95 
1,050 


34. 50 
84. 70 
4.00 


14B 


15B 


1908 to 1913: 

120 


130 


None. 
None. 
17.5 


40 
1,420 
630 


90 
220 
None. 


225 
1,080 
35 


42. 50 
7. 35 
32. 40 


140 


150 





Table XX shows that the wheat yields on the '^B" series are 
greatly in favor of the plats which produced an intertilled crop in 
alternate years, the differences in acre yields var^i^ng from 8 to 9 
bushels. In addition to yielding as much wheat as plat 12C, the 



TILLAGE AND ROTATION EXPERIMENTS AT NEPHI^ UTAH. 43 

other plats on the "C" series have given good yields of the intertilled 
crops. From these results it appears that the production of inter- 
tilled crops had some effect on the soil which was beneficial to the 
following wheat crop. It is difficult to determine the nature of this 
effect, but that it was present can not be doubted. 

The intertilled crops were sometimes unprofitable, in some instances 
total failures, but the losses thus accruing were offset by profitable 
yields in more favorable seasons. The cost of growing these crops 
was somewhat higher than the cost of maintaining fallow, but the 
yields of the intertilled crops and the higher wheat yields following 
made up for this difference in cost. It is quite impossible to deter- 
mine with any great degree of satisfaction the relative value of these 
rotations, since the total yields of some of the intertilled crops were 
so small, and because the production of such crops on the dry lands 
of the Great Basin is practically unheard of, there is no standard for 
estimating values. Perhaps the greatest value that will come from 
the results of the above experiment will be to point out the possibili- 
ties of such a rotation and to encourage greater effort in the develop- 
ment of better varieties of intertilled crops or better methods of pro- 
ducing the varieties now used. 

SUMMARY. 

The Nephi substation is located in the Juab Valley, in the eastern 
part of Juab County, in central Utah. The soil in this locality is 
very deep. It ranges from clay to sandy loam. In the virgin state 
it is covered with a dense growth of black sagebrush. 

The average annual precipitation in the Juab VaUey during the 
past 16 years was 13.40 inches. During the progress of the experi- 
ments reported herein (1908 to 1913), the precipitation in 1908 and 
1909 was above normal, while in 1910, 1911, 1912, and 1913 it was 
below normal. The winter and spring precipitation is the heaviest 
of the year. The rains of summer have been small and consequently 
of little value to the growing crops. 

The average evaporation at the Nephi substation during the six 
months from April to September, inclusive, has been about 45 inches. 
The avera-ge mnd velocity for any one day has not exceeded 10 miles 
per hour. Protracted hot winds are unknown. Only two months 
of the year, July and August, have been free from frost. Normally, 
however, there are from 90 to 100 days in the frost-free period, ex- 
tending from about June 15 to September 15. 

Most of the experiments reported upon have been in progress 
since 1908. A few are of longer duration, while some were begun 
as late as 1911. The tests have dealt with stubble treatment imme- 
diately after harvest; time and depth of plowing; cultivation of 



44 BULLETIN 157, U. S. DEPARTMENT OF AGEICULTUEE. 

fallow; seeding, cultivation, and harvesting the crop; frequency of 
cropping; and diversity of crops in rotation. 

The tests deahng with stubble treatment immediately after harvest 
were begun in the fall of 1911. The results so far obtained are not 
conclusive enough to warrant publication. 

The average results for five years, 1909 to 1913, inclusive, show 
that spring plowing was better than fall plowing for moisture con- 
servation, in yield of grain, and in cost of producing the crop. Spring 
plowing gave an average yield of 18.5 bushels per acre, as compared 
with 16.8 bushels for fall plowing. Owing to this difference in yield 
and the lower cost of producing the crop, spring plowing gave a net 
acre profit of $3.03 more than fall plowing. 

The results of five years show that there was no advantage in 
deep plowing or subsoifing over shallow plowing so far as moisture 
conservation is concerned. There was no material difference in the 
yields obtained from plats plowed at different depths, varjring from 
5 to 18 inches. The highest average yield was obtained from plats 
plowed 10 inches deep, and the lowest average yield was from the 
plats subsoiled 18 inches deep, while the 5-inch plowing yielded 
higher than the 15-inch subsoiling. 

One year's results from a test of deep fall plowing and shallow 
spring plowing compared with shallow fall plowing and deep spring 
plowing show no difference in soil moisture and but slight difference 
in yield. 

The results of five years' experiments on fall-plowed fallow show 
that the moisture of the cultivated plats remained practically the 
same throughout the season, while that of the uncultivated plats 
rapidly declined, until by fall it was reduced to a comparatively 
low point. It is probable that weeds and volunteer grain were 
important factors in this loss of moisture. The average acre yield 
of the cultivated plats was 17 bushels, as compared with 13 bushels 
on the uncultivated plats. 

The results of one season on spring-plowed fallow show no differ- 
ence in the moisture content of the plats cultivated or not cultivated. 
The yields, 11.9 and 9.5 bushels per acre, favor the noncultivated 
plat. 

The results of 10 years show no correlation between the time of 
sowing winter wheat and the yield, but the best yields have usually 
been obtained from plats seeded between September 1 and October 
15. There was no significant difi'erence between the average mois- 
ture content of the plats for any one or for all years. The chief 
problem in the time-of-seeding tests of winter wheat now seems to be 
a mechanical one involving some improvement of the machinery 
used in seeding. It is believed that this will obviate the necessity of 



TILLAGE AXD EOTATIOX EXPEEIMEXTS AT XEPHI, UTAH. 45 



waiting for rain before seeding, thus permitting early seeding, which 
seems desirable, and allowing the crop time enough to make a fair 
growth before the advent of winter. Late planting is often followed 
by much winterkilling, which completely offsets the value of any 
tillage method used in preparing the land and of the quantity of 
moisture stored in it. 

The average result of five years' tests shows no difference in the 
yields of winter wheat seeded at different depths. The yields were 
greatly influenced by conchtions at see<;hng time. 

The ordinary drilling of winter wheat has given more profitable 
yields than broadcasting or cross drilling. 

The residts of three years' experiments show that winter wheat 
sown at the rate of 4 to 5 pecks per acre is more profitable than when 
sown at 3 pecks per acre, the rate ordinarily used on the dry lands of 
the Great Basin. 

The average yields of five years favor no spring cultivation of 
winter wheat. The noncultivated plats yielded 17.05 bushels, 
as compared with 15.99 bushels from those cultivated. There was 
no apparent difference in the moisture content of the plats. A test 
made in the spring of 1913 showed that 11.54 per cent of the plants 
were killed by one harrowing. This loss offsets all benefits that might 
have come from harrowing. 

The results of four years favor harvesting when the grain is in 
the hard-dough stage. 

Where a good stand was obtained and little winterkilling followed^ 
winter wheat after fallow yielded more than winter wheat on con- 
tinuously cropped land. This depended largely upon the season, 
however, and the continuously cropped plat, owing to volunteer 
grain, yielded as weU or better than other plats in the test in seasons 
of much winter kill ing. 

The average acre yield of winter wheat for five years was less 
after fallow than after corn, potatoes, or peas. 



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